[Fix #480] Run tests on CircleCI

Author: bbatsov

.circleci/config.yml

@@ -0,0 +1,45 @@
+version: 2.1
+
+# Default actions to perform on each Emacs version
+default: &default-steps
+  steps:
+    - checkout
+    - run: apt-get update && apt-get install make
+    - run: make elpa
+    - run: emacs --version
+    - run: ./run-tests-ci.sh
+
+# Enumerated list of Emacs versions
+jobs:
+  test-emacs-25:
+    docker:
+      - image: silex/emacs:25-ci-cask
+        entrypoint: bash
+    <<: *default-steps
+
+  test-emacs-26:
+    docker:
+      - image: silex/emacs:26-ci-cask
+        entrypoint: bash
+    <<: *default-steps
+
+  test-emacs-27:
+    docker:
+      - image: silex/emacs:27-ci-cask
+        entrypoint: bash
+    <<: *default-steps
+
+  test-emacs-master:
+    docker:
+      - image: silex/emacs:master-ci-cask
+        entrypoint: bash
+    <<: *default-steps
+
+workflows:
+  version: 2
+  ci-test-matrix:
+    jobs:
+      - test-emacs-25
+      - test-emacs-26
+      - test-emacs-27
+      - test-emacs-master

.travis.yml

@@ -1,8 +1,10 @@
 [![MELPA](http://melpa.org/packages/clj-refactor-badge.svg)](http://melpa.org/#/clj-refactor)
 [![MELPA Stable](http://stable.melpa.org/packages/clj-refactor-badge.svg)](http://stable.melpa.org/#/clj-refactor)
-[![Build Status](https://secure.travis-ci.org/clojure-emacs/clj-refactor.el.png?branch=master)](http://travis-ci.org/clojure-emacs/clj-refactor.el)
+[![circleci][badge-circleci]][circleci]
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/clojure-emacs/refactor-nrepl?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
 
+[circleci]: https://circleci.com/gh/clojure-emacs/clj-refactor.el
+
 # clj-refactor.el
 
 `clj-refactor` provides refactoring support for Clojure projects. It complements