Add coverage tracking in nodejs + coveralls support

package.json

@@ -12,6 +12,7 @@
     "gulp": "^3.9.1",
     "gulp-tslint": "^8.1.2",
     "gulp-typescript": "^3.2.3",
+    "gulp-sourcemaps": "^2.6.4",
     "tslint": "^5.8.0",
     "typescript": "^2.6.2",
     "webpack": "^3.10.0",
@@ -22,11 +23,16 @@
     "karma-sauce-launcher": "^1.2.0",
     "karma-webpack": "^2.0.9",
     "karma-sourcemap-loader": "^0.3.7",
-    "ts-loader": "^3.3.1"
+    "ts-loader": "^3.3.1",
+    "istanbul": "^0.4.5",
+    "gulp-istanbul": "^1.1.3",
+    "remap-istanbul": "^0.10.1",
+    "coveralls": "^3.0.0"
   },
   "scripts": {
     "test": "gulp test",
     "lint": "gulp lint",
+    "cover": "gulp coverage",
     "browser-test": "karma start"
   },
   "repository": {