Add code coverage via coveralls.io

.coveralls.yml

@@ -0,0 +1 @@
+repo_token: LkTCt0dj8vmeTDkJpIRkVeoTUoCkO3CUZ

.gitignore

@@ -1,2 +1,4 @@
 node_modules
 lib
+coverage
+npm-debug.log

README.md

@@ -4,6 +4,7 @@ previous-date-range
 Calculate a date range in the past from a certain moment
 
 [![Build status](https://api.travis-ci.org/jamiter/previous-date-range.png)](https://travis-ci.org/jamiter/previous-date-range)
+[![Coverage Status](https://coveralls.io/repos/github/jamiter/previous-date-range/badge.svg)](https://coveralls.io/github/jamiter/previous-date-range)
 
 ## Installation
 

package.json

@@ -6,7 +6,8 @@
   "scripts": {
     "prepublish": "npm test -s",
     "build": "babel src -d lib",
-    "cover": "istanbul cover --report json _mocha -- -R spec --compilers js:babel-core/register './tests/**/*.js'",
+    "cover": "istanbul cover --report lcovonly _mocha -- -R spec --compilers js:babel-core/register './tests/**/*.js'",
+    "coveralls": "npm run cover && cat ./coverage/lcov.info | coveralls && rm -rf ./coverage",
     "lint": "eslint ./src ./test",
     "mocha": "npm run build -s && _mocha -R spec --compilers js:babel-core/register './tests/**/*.js'",
     "start": "npm run build -s -- -w",
@@ -35,6 +36,7 @@
     "babel-plugin-transform-object-rest-spread": "^6.20.2",
     "babel-preset-env": "^1.1.8",
     "chai": "^3.5.0",
+    "coveralls": "^2.11.15",
     "eslint": "^3.13.1",
     "eslint-config-airbnb-base": "^11.0.1",
     "eslint-plugin-import": "^2.2.0",