chore: add circleci config and readme badges

.circleci/config.yml

@@ -0,0 +1,35 @@
+# Javascript Node CircleCI 2.0 configuration file
+#
+# Check https://circleci.com/docs/2.0/language-javascript/ for more details
+#
+
+default-test-config: &default-test-config
+  working_directory: ~/repo
+  steps:
+    - checkout
+    - restore_cache:
+        key: dependencies-{{ checksum "yarn.lock" }}
+    - run: yarn install
+    - save_cache:
+        paths:
+          - node_modules
+        key: dependencies-{{ checksum "yarn.lock" }}
+    - run: yarn test
+
+version: 2
+jobs:
+  test-node-8:
+    <<: *default-test-config
+    docker:
+      - image: circleci/node:8.9.4
+  test-node-9:
+    <<: *default-test-config
+    docker:
+      - image: circleci/node:9.5.0
+
+workflows:
+  version: 2
+  test:
+    jobs:
+      - "test-node-8"
+      - "test-node-9"

README.md

@@ -1,10 +1,9 @@
 # denali-babel
 
-[![NPM version][npm-image]][npm-url]
-[![Build Status][travis-image]][travis-url]
-[![Coverage][coverage-image]][coverage-url]
-[![Dependency Status][depstat-image]][depstat-url]
-[![Downloads][download-image]][npm-url]
+[![CircleCI](https://img.shields.io/circleci/project/github/denali-js/denali-babel.svg?style=flat-square)](https://circleci.com/gh/denali-js/denali-babel)
+[![Dependencies](https://img.shields.io/david/denali-js/denali-babel.svg?style=flat-square)](https://david-dm.org/denali-js/denali-babel)
+[![npm downloads](https://img.shields.io/npm/dm/denali-babel.svg?style=flat-square)](https://www.npmjs.com/package/denali-babel)
+![latest version](https://img.shields.io/npm/v/denali-babel.svg?style=flat-square)
 
 Transpile your Denali app using Babel.
 
@@ -22,18 +21,3 @@ This file is how you tell Babel what transforms to apply, as well which files to
 transformation.
 
 For more details, check out [the Babel docs](https://babeljs.io/docs/usage/babelrc/).
-
-
-[npm-url]: https://npmjs.org/package/denali-babel
-[npm-image]: https://img.shields.io/npm/v/denali-babel.svg?style=flat-square
-
-[travis-url]: https://travis-ci.org/denali-js/denali-babel
-[travis-image]: https://img.shields.io/travis/denali-js/denali-babel/master.svg?style=flat-square
-
-[coverage-url]: https://codeclimate.com/github/denali-js/denali-babel
-[coverage-image]: https://img.shields.io/codeclimate/coverage/github/denali-js/denali-babel.svg?style=flat-square
-
-[depstat-url]: https://david-dm.org/denali-js/denali-babel
-[depstat-image]: https://david-dm.org/denali-js/denali-babel/status.svg?style=flat-square
-
-[download-image]: https://img.shields.io/npm/dm/denali-babel.svg?style=flat-square