add tests

package.json

@@ -9,6 +9,7 @@
   "author": "Microsoft Corporation",
   "license": "MIT",
   "scripts": {
+    "test": "mocha",
     "prepublish": "gulp compile"
   },
   "dependencies": {
@@ -29,6 +30,7 @@
     "gulp": "^3.9.0",
     "gulp-filter": "^3.0.1",
     "gulp-tsb": "^1.6.0",
+    "mocha": "^2.3.3",
     "rimraf": "^2.4.3"
   }
-}
+}

test/mocha.opts

@@ -0,0 +1 @@
+--compilers js:babel/register