add Circle CI support

.circleci/config.yml

@@ -0,0 +1,38 @@
+version: 2.1
+
+commands:
+  run-tests:
+    steps:
+      - checkout
+      - restore_cache:
+          key: dependency-cache-{{ checksum "package.json" }}
+      - run:
+          name: Installing Dependencies
+          command: npm install
+      - save_cache:
+          key: dependency-cache-{{ checksum "package.json" }}
+          paths:
+            - ./node_modules
+      - run:
+          name: Lint Source
+          command: npm run test
+
+jobs:
+  node-latest:
+    docker:
+      - image: circleci/node:latest
+    steps:
+      - run-tests
+
+  node-lts:
+    docker:
+      - image: circleci/node:lts
+    steps:
+      - run-tests
+
+workflows:
+  node-multi-build:
+    jobs:
+    - node-latest
+    - node-lts
+  version: 2

.npmignore

@@ -1,3 +1,4 @@
+.circle-ci
 bower.json
 gulpfile.js
 yarn.lock