use circleci instead of travis

.circleci/config.yml

@@ -0,0 +1,66 @@
+# Javascript Node CircleCI 2.0 configuration file
+#
+# Check https://circleci.com/docs/2.0/language-javascript/ for more details
+#
+# Caching environmental variable workaround:
+# https://discuss.circleci.com/t/cannot-use-circle-yml-environment-variables-in-cache-keys/10994/9
+#
+
+version: 2
+jobs:
+    test-node6:
+        docker:
+            - image: circleci/node:6
+        steps:
+            - checkout
+            - run: node --version > _node_version && npm --version > _npm_version && cat _node_version && cat _npm_version
+            - restore_cache:
+                  keys:
+                      - v1-dependencies-{{ checksum "_node_version" }}-{{ checksum "_npm_version" }}
+            - run: node --version && npm --version
+            - run: npm install
+            - save_cache:
+                  paths:
+                      - ~/.npm
+                  key: v1-dependencies-{{ checksum "_node_version" }}-{{ checksum "_npm_version" }}
+            - run: npm run test.ci
+    test-node8:
+        docker:
+            - image: circleci/node:8
+        steps:
+            - checkout
+            - run: node --version > _node_version && npm --version > _npm_version && cat _node_version && cat _npm_version
+            - restore_cache:
+                  keys:
+                      - v1-dependencies-{{ checksum "_node_version" }}-{{ checksum "_npm_version" }}
+            - run: node --version && npm --version
+            - run: npm install
+            - save_cache:
+                  paths:
+                      - ~/.npm
+                  key: v1-dependencies-{{ checksum "_node_version" }}-{{ checksum "_npm_version" }}
+            - run: npm run test.ci
+    test-node10:
+        docker:
+            - image: circleci/node:10
+        steps:
+            - checkout
+            - run: node --version > _node_version && npm --version > _npm_version && cat _node_version && cat _npm_version
+            - restore_cache:
+                  keys:
+                      - v1-dependencies-{{ checksum "_node_version" }}-{{ checksum "_npm_version" }}
+            - run: node --version && npm --version
+            - run: npm install
+            - save_cache:
+                  paths:
+                      - ~/.npm
+                  key: v1-dependencies-{{ checksum "_node_version" }}-{{ checksum "_npm_version" }}
+            - run: npm run test.ci
+
+workflows:
+    version: 2
+    build_and_test:
+        jobs:
+            - test-node6
+            - test-node8
+            - test-node10

README.md

@@ -2,16 +2,16 @@
 
 [![npm][npm-image]][npm-url]
 [![MIT License][mit-license-image]][mit-license-url]
-[![Linux Build Status][travis-image]][travis-url]
+[![Linux Build Status][circleci-image]][circleci-url]
 [![Windows Build Status][appveyor-image]][appveyor-url]
 [![Coveralls Status][coveralls-image]][coveralls-url]
 
 [npm-url]: https://www.npmjs.com/package/clean-webpack-plugin
 [npm-image]: https://img.shields.io/npm/v/clean-webpack-plugin.svg?label=npm%20version
 [mit-license-url]: LICENSE
 [mit-license-image]: https://camo.githubusercontent.com/d59450139b6d354f15a2252a47b457bb2cc43828/68747470733a2f2f696d672e736869656c64732e696f2f6e706d2f6c2f7365727665726c6573732e737667
-[travis-url]: https://travis-ci.org/johnagan/clean-webpack-plugin
-[travis-image]: https://img.shields.io/travis/johnagan/clean-webpack-plugin/master.svg?label=linux%20build
+[circleci-url]: https://circleci.com/gh/johnagan/clean-webpack-plugin/tree/master
+[circleci-image]: https://img.shields.io/circleci/project/github/johnagan/clean-webpack-plugin/master.svg?label=linux%20build
 [appveyor-url]: https://ci.appveyor.com/project/johnagan/clean-webpack-plugin/branch/master
 [appveyor-image]: https://img.shields.io/appveyor/ci/johnagan/clean-webpack-plugin/master.svg?label=windows%20build
 [coveralls-url]: https://codecov.io/gh/johnagan/clean-webpack-plugin/branch/master