Updated docker build to reduce image size. (#18)

diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..2d0cf6f
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,8 @@
+.git
+CONTRIBUTING.md
+Dockerfile
+LICENSE
+NOTICE
+.asf.yaml
+.dockerignore
+.gitignore
diff --git a/Dockerfile b/Dockerfile
index 9b56005..7dc3921 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -62,16 +62,16 @@
      download_bin "fluo.tar.gz" "$FLUO_HASH" "fluo/fluo/$FLUO_VERSION/fluo-$FLUO_VERSION-bin.tar.gz"; \
    else \
      cp "/tmp/$FLUO_FILE" "fluo.tar.gz"; \
-   fi
-RUN tar xzf hadoop.tar.gz -C /tmp/
-RUN tar xzf zookeeper.tar.gz -C /tmp/
-RUN tar xzf accumulo.tar.gz -C /tmp/
-RUN tar xzf fluo.tar.gz -C /tmp/
-
-RUN mv /tmp/hadoop-$HADOOP_VERSION /opt/hadoop
-RUN mv /tmp/zookeeper-$ZOOKEEPER_VERSION /opt/zookeeper
-RUN mv /tmp/accumulo-$ACCUMULO_VERSION /opt/accumulo
-RUN mv /tmp/fluo-$FLUO_VERSION /opt/fluo
+   fi && \
+  tar xzf hadoop.tar.gz -C /tmp/ && \
+  tar xzf zookeeper.tar.gz -C /tmp/ && \
+  tar xzf accumulo.tar.gz -C /tmp/ && \
+  tar xzf fluo.tar.gz -C /tmp/ && \
+  mv /tmp/hadoop-$HADOOP_VERSION /opt/hadoop && \
+  mv /tmp/zookeeper-$ZOOKEEPER_VERSION /opt/zookeeper && \
+  mv /tmp/accumulo-$ACCUMULO_VERSION /opt/accumulo && \
+  mv /tmp/fluo-$FLUO_VERSION /opt/fluo && \
+  /opt/fluo/lib/fetch.sh extra
 
 ENV HADOOP_PREFIX /opt/hadoop
 ENV HADOOP_HOME /opt/hadoop
@@ -80,7 +80,5 @@
 ENV FLUO_HOME /opt/fluo
 ENV PATH "$PATH:$FLUO_HOME/bin"
 
-RUN /opt/fluo/lib/fetch.sh extra
-
 ENTRYPOINT ["fluo"]
 CMD ["help"]