Add code coverage.

package.json

@@ -4,7 +4,7 @@
   "description": "Matrix Client-Server SDK for Javascript",
   "main": "index.js",
   "scripts": {
-    "test": "jasmine-node spec --verbose --captureExceptions",
+    "test": "istanbul cover --report cobertura -x **/examples/**/*.js jasmine-node -- spec --verbose --junitreport --forceexit --captureExceptions",
     "build": "jshint -c .jshint lib/ && browserify browser-index.js -o dist/browser-matrix-dev.js",
     "watch": "watchify browser-index.js -o dist/browser-matrix-dev.js -v"
   },
@@ -25,6 +25,7 @@
   },
   "devDependencies": {
     "watchify": "^3.2.1",
+    "istanbul": "^0.3.13",
     "jasmine-node": "^1.14.5",
     "jshint": "^2.8.0"
   }