Add Test Coverage with nyc package and coveralls for github badge

.gitignore

@@ -24,4 +24,7 @@ test/background.js
 test/bundle.js
 test/test-bundle.js
 
-notes.txt
+notes.txt
+
+.coveralls.yml
+.nyc_output

README.md

@@ -1,4 +1,4 @@
-# MetaMask Plugin [![Build Status](https://circleci.com/gh/MetaMask/metamask-extension.svg?style=shield&circle-token=a1ddcf3cd38e29267f254c9c59d556d513e3a1fd)](https://circleci.com/gh/MetaMask/metamask-extension)
+# MetaMask Plugin [![Build Status](https://circleci.com/gh/MetaMask/metamask-extension.svg?style=shield&circle-token=a1ddcf3cd38e29267f254c9c59d556d513e3a1fd)](https://circleci.com/gh/MetaMask/metamask-extension) [![Coverage Status](https://coveralls.io/repos/github/MetaMask/metamask-extension/badge.svg?branch=master)](https://coveralls.io/github/MetaMask/metamask-extension?branch=master)
 
 ## Support
 

package.json

@@ -13,6 +13,7 @@
     "test-unit": "METAMASK_ENV=test mocha --require test/helper.js --recursive \"test/unit/**/*.js\"",
     "single-test": "METAMASK_ENV=test mocha --require test/helper.js",
     "test-integration": "npm run buildMock && npm run buildCiUnits && testem ci -P 2",
+    "test-coverage": "nyc --reporter=text npm run test-unit",
     "lint": "gulp lint",
     "buildCiUnits": "node test/integration/index.js",
     "watch": "mocha watch --recursive \"test/unit/**/*.js\"",
@@ -144,6 +145,7 @@
     "brfs": "^1.4.3",
     "browserify": "^13.0.0",
     "chai": "^3.5.0",
+    "coveralls": "^2.13.1",
     "deep-freeze-strict": "^1.1.1",
     "del": "^2.2.0",
     "envify": "^4.0.0",
@@ -170,6 +172,7 @@
     "mocha-jsdom": "^1.1.0",
     "mocha-sinon": "^1.1.5",
     "nock": "^8.0.0",
+    "nyc": "^11.0.3",
     "open": "0.0.5",
     "prompt": "^1.0.0",
     "qs": "^6.2.0",