[hotfix] Remove deprecated 1.8 Dockerfiles

This closes #7.
diff --git a/1.8/scala_2.11-debian/Dockerfile b/1.8/scala_2.11-debian/Dockerfile
deleted file mode 100644
index 85006c7..0000000
--- a/1.8/scala_2.11-debian/Dockerfile
+++ /dev/null
@@ -1,89 +0,0 @@
-###############################################################################
-#  Licensed to the Apache Software Foundation (ASF) under one
-#  or more contributor license agreements.  See the NOTICE file
-#  distributed with this work for additional information
-#  regarding copyright ownership.  The ASF licenses this file
-#  to you under the Apache License, Version 2.0 (the
-#  "License"); you may not use this file except in compliance
-#  with the License.  You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-#  Unless required by applicable law or agreed to in writing, software
-#  distributed under the License is distributed on an "AS IS" BASIS,
-#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-#  See the License for the specific language governing permissions and
-# limitations under the License.
-###############################################################################
-
-FROM openjdk:8-jre
-
-# Install dependencies
-RUN set -ex; \
-  apt-get update; \
-  apt-get -y install libsnappy1v5 gettext-base; \
-  rm -rf /var/lib/apt/lists/*
-
-# Grab gosu for easy step-down from root
-ENV GOSU_VERSION 1.11
-RUN set -ex; \
-  wget -nv -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture)"; \
-  wget -nv -O /usr/local/bin/gosu.asc "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture).asc"; \
-  export GNUPGHOME="$(mktemp -d)"; \
-  for server in ha.pool.sks-keyservers.net $(shuf -e \
-                          hkp://p80.pool.sks-keyservers.net:80 \
-                          keyserver.ubuntu.com \
-                          hkp://keyserver.ubuntu.com:80 \
-                          pgp.mit.edu) ; do \
-      gpg --batch --keyserver "$server" --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4 && break || : ; \
-  done && \
-  gpg --batch --verify /usr/local/bin/gosu.asc /usr/local/bin/gosu; \
-  gpgconf --kill all; \
-  rm -rf "$GNUPGHOME" /usr/local/bin/gosu.asc; \
-  chmod +x /usr/local/bin/gosu; \
-  gosu nobody true
-
-# Configure Flink version
-ENV FLINK_VERSION=1.8.3 \
-    SCALA_VERSION=2.11 \
-    GPG_KEY=EF88474C564C7A608A822EEC3FF96A2057B6476C
-
-# Prepare environment
-ENV FLINK_HOME=/opt/flink
-ENV PATH=$FLINK_HOME/bin:$PATH
-RUN groupadd --system --gid=9999 flink && \
-    useradd --system --home-dir $FLINK_HOME --uid=9999 --gid=flink flink
-WORKDIR $FLINK_HOME
-
-ENV FLINK_URL_FILE_PATH=flink/flink-${FLINK_VERSION}/flink-${FLINK_VERSION}-bin-scala_${SCALA_VERSION}.tgz
-# Not all mirrors have the .asc files
-ENV FLINK_TGZ_URL=https://www.apache.org/dyn/closer.cgi?action=download&filename=${FLINK_URL_FILE_PATH} \
-    FLINK_ASC_URL=https://www.apache.org/dist/${FLINK_URL_FILE_PATH}.asc
-
-# Install Flink
-RUN set -ex; \
-  wget -nv -O flink.tgz "$FLINK_TGZ_URL"; \
-  wget -nv -O flink.tgz.asc "$FLINK_ASC_URL"; \
-  \
-  export GNUPGHOME="$(mktemp -d)"; \
-  for server in ha.pool.sks-keyservers.net $(shuf -e \
-                          hkp://p80.pool.sks-keyservers.net:80 \
-                          keyserver.ubuntu.com \
-                          hkp://keyserver.ubuntu.com:80 \
-                          pgp.mit.edu) ; do \
-      gpg --batch --keyserver "$server" --recv-keys "$GPG_KEY" && break || : ; \
-  done && \
-  gpg --batch --verify flink.tgz.asc flink.tgz; \
-  gpgconf --kill all; \
-  rm -rf "$GNUPGHOME" flink.tgz.asc; \
-  \
-  tar -xf flink.tgz --strip-components=1; \
-  rm flink.tgz; \
-  \
-  chown -R flink:flink .;
-
-# Configure container
-COPY docker-entrypoint.sh /
-ENTRYPOINT ["/docker-entrypoint.sh"]
-EXPOSE 6123 8081
-CMD ["help"]
diff --git a/1.8/scala_2.11-debian/docker-entrypoint.sh b/1.8/scala_2.11-debian/docker-entrypoint.sh
deleted file mode 100755
index 2858f8a..0000000
--- a/1.8/scala_2.11-debian/docker-entrypoint.sh
+++ /dev/null
@@ -1,109 +0,0 @@
-#!/bin/sh
-
-###############################################################################
-#  Licensed to the Apache Software Foundation (ASF) under one
-#  or more contributor license agreements.  See the NOTICE file
-#  distributed with this work for additional information
-#  regarding copyright ownership.  The ASF licenses this file
-#  to you under the Apache License, Version 2.0 (the
-#  "License"); you may not use this file except in compliance
-#  with the License.  You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-#  Unless required by applicable law or agreed to in writing, software
-#  distributed under the License is distributed on an "AS IS" BASIS,
-#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-#  See the License for the specific language governing permissions and
-# limitations under the License.
-###############################################################################
-
-# If unspecified, the hostname of the container is taken as the JobManager address
-JOB_MANAGER_RPC_ADDRESS=${JOB_MANAGER_RPC_ADDRESS:-$(hostname -f)}
-CONF_FILE="${FLINK_HOME}/conf/flink-conf.yaml"
-
-drop_privs_cmd() {
-    if [ $(id -u) != 0 ]; then
-        # Don't need to drop privs if EUID != 0
-        return
-    elif [ -x /sbin/su-exec ]; then
-        # Alpine
-        echo su-exec flink
-    else
-        # Others
-        echo gosu flink
-    fi
-}
-
-if [ "$1" = "help" ]; then
-    echo "Usage: $(basename "$0") (jobmanager|taskmanager|help)"
-    exit 0
-elif [ "$1" = "jobmanager" ]; then
-    shift 1
-    echo "Starting Job Manager"
-
-    if grep -E "^jobmanager\.rpc\.address:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/jobmanager\.rpc\.address:.*/jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}/g" "${CONF_FILE}"
-    else
-        echo "jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^blob\.server\.port:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/blob\.server\.port:.*/blob.server.port: 6124/g" "${CONF_FILE}"
-    else
-        echo "blob.server.port: 6124" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^query\.server\.port:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/query\.server\.port:.*/query.server.port: 6125/g" "${CONF_FILE}"
-    else
-        echo "query.server.port: 6125" >> "${CONF_FILE}"
-    fi
-
-    if [ -n "${FLINK_PROPERTIES}" ]; then
-        echo "${FLINK_PROPERTIES}" >> "${CONF_FILE}"
-    fi
-    envsubst < "${CONF_FILE}" > "${CONF_FILE}.tmp" && mv "${CONF_FILE}.tmp" "${CONF_FILE}"
-
-    echo "config file: " && grep '^[^\n#]' "${CONF_FILE}"
-    exec $(drop_privs_cmd) "$FLINK_HOME/bin/jobmanager.sh" start-foreground "$@"
-elif [ "$1" = "taskmanager" ]; then
-    shift 1
-    echo "Starting Task Manager"
-
-    TASK_MANAGER_NUMBER_OF_TASK_SLOTS=${TASK_MANAGER_NUMBER_OF_TASK_SLOTS:-$(grep -c ^processor /proc/cpuinfo)}
-
-    if grep -E "^jobmanager\.rpc\.address:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/jobmanager\.rpc\.address:.*/jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}/g" "${CONF_FILE}"
-    else
-        echo "jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^taskmanager\.numberOfTaskSlots:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/taskmanager\.numberOfTaskSlots:.*/taskmanager.numberOfTaskSlots: ${TASK_MANAGER_NUMBER_OF_TASK_SLOTS}/g" "${CONF_FILE}"
-    else
-        echo "taskmanager.numberOfTaskSlots: ${TASK_MANAGER_NUMBER_OF_TASK_SLOTS}" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^blob\.server\.port:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/blob\.server\.port:.*/blob.server.port: 6124/g" "${CONF_FILE}"
-    else
-        echo "blob.server.port: 6124" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^query\.server\.port:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/query\.server\.port:.*/query.server.port: 6125/g" "${CONF_FILE}"
-    else
-        echo "query.server.port: 6125" >> "${CONF_FILE}"
-    fi
-
-    if [ -n "${FLINK_PROPERTIES}" ]; then
-        echo "${FLINK_PROPERTIES}" >> "${CONF_FILE}"
-    fi
-    envsubst < "${CONF_FILE}" > "${CONF_FILE}.tmp" && mv "${CONF_FILE}.tmp" "${CONF_FILE}"
-
-    echo "config file: " && grep '^[^\n#]' "${CONF_FILE}"
-    exec $(drop_privs_cmd) "$FLINK_HOME/bin/taskmanager.sh" start-foreground "$@"
-fi
-
-exec "$@"
diff --git a/1.8/scala_2.12-debian/Dockerfile b/1.8/scala_2.12-debian/Dockerfile
deleted file mode 100644
index c89ae54..0000000
--- a/1.8/scala_2.12-debian/Dockerfile
+++ /dev/null
@@ -1,89 +0,0 @@
-###############################################################################
-#  Licensed to the Apache Software Foundation (ASF) under one
-#  or more contributor license agreements.  See the NOTICE file
-#  distributed with this work for additional information
-#  regarding copyright ownership.  The ASF licenses this file
-#  to you under the Apache License, Version 2.0 (the
-#  "License"); you may not use this file except in compliance
-#  with the License.  You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-#  Unless required by applicable law or agreed to in writing, software
-#  distributed under the License is distributed on an "AS IS" BASIS,
-#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-#  See the License for the specific language governing permissions and
-# limitations under the License.
-###############################################################################
-
-FROM openjdk:8-jre
-
-# Install dependencies
-RUN set -ex; \
-  apt-get update; \
-  apt-get -y install libsnappy1v5 gettext-base; \
-  rm -rf /var/lib/apt/lists/*
-
-# Grab gosu for easy step-down from root
-ENV GOSU_VERSION 1.11
-RUN set -ex; \
-  wget -nv -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture)"; \
-  wget -nv -O /usr/local/bin/gosu.asc "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture).asc"; \
-  export GNUPGHOME="$(mktemp -d)"; \
-  for server in ha.pool.sks-keyservers.net $(shuf -e \
-                          hkp://p80.pool.sks-keyservers.net:80 \
-                          keyserver.ubuntu.com \
-                          hkp://keyserver.ubuntu.com:80 \
-                          pgp.mit.edu) ; do \
-      gpg --batch --keyserver "$server" --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4 && break || : ; \
-  done && \
-  gpg --batch --verify /usr/local/bin/gosu.asc /usr/local/bin/gosu; \
-  gpgconf --kill all; \
-  rm -rf "$GNUPGHOME" /usr/local/bin/gosu.asc; \
-  chmod +x /usr/local/bin/gosu; \
-  gosu nobody true
-
-# Configure Flink version
-ENV FLINK_VERSION=1.8.3 \
-    SCALA_VERSION=2.12 \
-    GPG_KEY=EF88474C564C7A608A822EEC3FF96A2057B6476C
-
-# Prepare environment
-ENV FLINK_HOME=/opt/flink
-ENV PATH=$FLINK_HOME/bin:$PATH
-RUN groupadd --system --gid=9999 flink && \
-    useradd --system --home-dir $FLINK_HOME --uid=9999 --gid=flink flink
-WORKDIR $FLINK_HOME
-
-ENV FLINK_URL_FILE_PATH=flink/flink-${FLINK_VERSION}/flink-${FLINK_VERSION}-bin-scala_${SCALA_VERSION}.tgz
-# Not all mirrors have the .asc files
-ENV FLINK_TGZ_URL=https://www.apache.org/dyn/closer.cgi?action=download&filename=${FLINK_URL_FILE_PATH} \
-    FLINK_ASC_URL=https://www.apache.org/dist/${FLINK_URL_FILE_PATH}.asc
-
-# Install Flink
-RUN set -ex; \
-  wget -nv -O flink.tgz "$FLINK_TGZ_URL"; \
-  wget -nv -O flink.tgz.asc "$FLINK_ASC_URL"; \
-  \
-  export GNUPGHOME="$(mktemp -d)"; \
-  for server in ha.pool.sks-keyservers.net $(shuf -e \
-                          hkp://p80.pool.sks-keyservers.net:80 \
-                          keyserver.ubuntu.com \
-                          hkp://keyserver.ubuntu.com:80 \
-                          pgp.mit.edu) ; do \
-      gpg --batch --keyserver "$server" --recv-keys "$GPG_KEY" && break || : ; \
-  done && \
-  gpg --batch --verify flink.tgz.asc flink.tgz; \
-  gpgconf --kill all; \
-  rm -rf "$GNUPGHOME" flink.tgz.asc; \
-  \
-  tar -xf flink.tgz --strip-components=1; \
-  rm flink.tgz; \
-  \
-  chown -R flink:flink .;
-
-# Configure container
-COPY docker-entrypoint.sh /
-ENTRYPOINT ["/docker-entrypoint.sh"]
-EXPOSE 6123 8081
-CMD ["help"]
diff --git a/1.8/scala_2.12-debian/docker-entrypoint.sh b/1.8/scala_2.12-debian/docker-entrypoint.sh
deleted file mode 100755
index 2858f8a..0000000
--- a/1.8/scala_2.12-debian/docker-entrypoint.sh
+++ /dev/null
@@ -1,109 +0,0 @@
-#!/bin/sh
-
-###############################################################################
-#  Licensed to the Apache Software Foundation (ASF) under one
-#  or more contributor license agreements.  See the NOTICE file
-#  distributed with this work for additional information
-#  regarding copyright ownership.  The ASF licenses this file
-#  to you under the Apache License, Version 2.0 (the
-#  "License"); you may not use this file except in compliance
-#  with the License.  You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-#  Unless required by applicable law or agreed to in writing, software
-#  distributed under the License is distributed on an "AS IS" BASIS,
-#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-#  See the License for the specific language governing permissions and
-# limitations under the License.
-###############################################################################
-
-# If unspecified, the hostname of the container is taken as the JobManager address
-JOB_MANAGER_RPC_ADDRESS=${JOB_MANAGER_RPC_ADDRESS:-$(hostname -f)}
-CONF_FILE="${FLINK_HOME}/conf/flink-conf.yaml"
-
-drop_privs_cmd() {
-    if [ $(id -u) != 0 ]; then
-        # Don't need to drop privs if EUID != 0
-        return
-    elif [ -x /sbin/su-exec ]; then
-        # Alpine
-        echo su-exec flink
-    else
-        # Others
-        echo gosu flink
-    fi
-}
-
-if [ "$1" = "help" ]; then
-    echo "Usage: $(basename "$0") (jobmanager|taskmanager|help)"
-    exit 0
-elif [ "$1" = "jobmanager" ]; then
-    shift 1
-    echo "Starting Job Manager"
-
-    if grep -E "^jobmanager\.rpc\.address:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/jobmanager\.rpc\.address:.*/jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}/g" "${CONF_FILE}"
-    else
-        echo "jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^blob\.server\.port:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/blob\.server\.port:.*/blob.server.port: 6124/g" "${CONF_FILE}"
-    else
-        echo "blob.server.port: 6124" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^query\.server\.port:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/query\.server\.port:.*/query.server.port: 6125/g" "${CONF_FILE}"
-    else
-        echo "query.server.port: 6125" >> "${CONF_FILE}"
-    fi
-
-    if [ -n "${FLINK_PROPERTIES}" ]; then
-        echo "${FLINK_PROPERTIES}" >> "${CONF_FILE}"
-    fi
-    envsubst < "${CONF_FILE}" > "${CONF_FILE}.tmp" && mv "${CONF_FILE}.tmp" "${CONF_FILE}"
-
-    echo "config file: " && grep '^[^\n#]' "${CONF_FILE}"
-    exec $(drop_privs_cmd) "$FLINK_HOME/bin/jobmanager.sh" start-foreground "$@"
-elif [ "$1" = "taskmanager" ]; then
-    shift 1
-    echo "Starting Task Manager"
-
-    TASK_MANAGER_NUMBER_OF_TASK_SLOTS=${TASK_MANAGER_NUMBER_OF_TASK_SLOTS:-$(grep -c ^processor /proc/cpuinfo)}
-
-    if grep -E "^jobmanager\.rpc\.address:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/jobmanager\.rpc\.address:.*/jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}/g" "${CONF_FILE}"
-    else
-        echo "jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^taskmanager\.numberOfTaskSlots:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/taskmanager\.numberOfTaskSlots:.*/taskmanager.numberOfTaskSlots: ${TASK_MANAGER_NUMBER_OF_TASK_SLOTS}/g" "${CONF_FILE}"
-    else
-        echo "taskmanager.numberOfTaskSlots: ${TASK_MANAGER_NUMBER_OF_TASK_SLOTS}" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^blob\.server\.port:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/blob\.server\.port:.*/blob.server.port: 6124/g" "${CONF_FILE}"
-    else
-        echo "blob.server.port: 6124" >> "${CONF_FILE}"
-    fi
-
-    if grep -E "^query\.server\.port:.*" "${CONF_FILE}" > /dev/null; then
-        sed -i -e "s/query\.server\.port:.*/query.server.port: 6125/g" "${CONF_FILE}"
-    else
-        echo "query.server.port: 6125" >> "${CONF_FILE}"
-    fi
-
-    if [ -n "${FLINK_PROPERTIES}" ]; then
-        echo "${FLINK_PROPERTIES}" >> "${CONF_FILE}"
-    fi
-    envsubst < "${CONF_FILE}" > "${CONF_FILE}.tmp" && mv "${CONF_FILE}.tmp" "${CONF_FILE}"
-
-    echo "config file: " && grep '^[^\n#]' "${CONF_FILE}"
-    exec $(drop_privs_cmd) "$FLINK_HOME/bin/taskmanager.sh" start-foreground "$@"
-fi
-
-exec "$@"