remove circleci; add 13 to nodejs matrix (#15)

diff --git a/.circleci/config.yml b/.circleci/config.yml
deleted file mode 100644
index 86fea3a..0000000
--- a/.circleci/config.yml
+++ /dev/null
@@ -1,78 +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.
-#
-version: 2
-workflows:
-  version: 2
-  build:
-    jobs:
-      - build-node-latest
-      - build-node-12
-      - build-node-10
-      - build-node-8
-
-jobs:
-  build-node-latest: &build-template
-    machine: true
-    environment:
-      NODE_VERSION: node
-    steps:
-      # fix for local builds https://github.com/CircleCI-Public/circleci-cli/issues/330
-      - run:
-          name: Local build handling
-          command: |
-            if [[ ${CIRCLE_SHELL_ENV} =~ "localbuild" ]]; then
-              if [ -d /workdir ]; then
-                ln -s /workdir /tmp/_circleci_local_build_repo
-              else
-                echo "Run this local build using: circleci build -v \$(pwd):/workdir"
-                exit 1
-              fi
-            fi
-      - checkout
-      - run:
-          name: Install node
-          command: |
-            if [ -d /opt/circleci/.nvm ]; then
-              echo 'export NVM_DIR="/opt/circleci/.nvm"' >> $BASH_ENV
-            else
-              curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.1/install.sh | bash
-              echo 'export NVM_DIR="$HOME/.nvm"' >> $BASH_ENV
-            fi
-            echo ' [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"' >> $BASH_ENV
-            source $BASH_ENV
-            nvm install $NODE_VERSION
-            nvm alias default $NODE_VERSION
-      - run: npm install
-      - run: npm test -- -v
-      - run: npm run report-coverage
-      - store_test_results:
-          path: test-results
-
-  build-node-12:
-    <<: *build-template
-    environment:
-      NODE_VERSION: 12
-
-  build-node-10:
-    <<: *build-template
-    environment:
-      NODE_VERSION: 10
-
-  build-node-8:
-    <<: *build-template
-    environment:
-      NODE_VERSION: 8
diff --git a/.travis.yml b/.travis.yml
index f97c220..39259be 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,6 +20,7 @@
   - 8
   - 10
   - 12
+  - 13
 services:
   - docker