Setup coveralls integration

Author: Trent Willis

.travis.yml

@@ -6,3 +6,6 @@ cache: yarn
 
 script:
   - yarn test
+
+after_success:
+  - yarn run coverage

README.md

@@ -1,6 +1,7 @@
 # Ember Best Practices
 
 [![Build Status](https://travis-ci.org/ember-best-practices/eslint-plugin-ember-best-practices.svg?branch=master)](https://travis-ci.org/ember-best-practices/eslint-plugin-ember-best-practices)
+[![Coverage Status](https://coveralls.io/repos/github/ember-best-practices/eslint-plugin-ember-best-practices/badge.svg?branch=master)](https://coveralls.io/github/ember-best-practices/eslint-plugin-ember-best-practices?branch=master)
 [![npm version](https://badge.fury.io/js/eslint-plugin-ember-best-practices.svg)](https://badge.fury.io/js/eslint-plugin-ember-best-practices)
 
 This adds more guard rails for Ember. Just because something "works" does not mean it is correct or in line with the framework's programming model. These footguns include:

package.json

@@ -8,6 +8,7 @@
     "test": "tests"
   },
   "scripts": {
+    "coverage": "nyc report --reporter=text-lcov | coveralls",
     "test": "nyc mocha --recursive tests",
     "test-server": "mocha --recursive --growl --watch tests"
   },
@@ -23,6 +24,7 @@
     "eslint-plugin"
   ],
   "devDependencies": {
+    "coveralls": "^2.13.1",
     "eslint": "^3.11.1",
     "mocha": "^3.2.0",
     "mocha-eslint": "^3.0.1",