Remove bluebird dependency

Author: enaqx

package.json

@@ -45,7 +45,6 @@
     "babel": "5.5.5",
     "babel-core": "5.5.5",
     "babel-eslint": "3.1.15",
-    "bluebird": "2.9.27",
     "chai": "3.0.0",
     "chai-as-promised": "5.1.0",
     "chai-subset": "1.0.1",