Add rsvp-module to npm devDependencies

Author: MikiDi

package.json

@@ -49,7 +49,8 @@
     "ember-load-initializers": "^0.5.1",
     "ember-resolver": "^2.0.3",
     "ember-try": "^0.2.2",
-    "loader.js": "^4.0.1"
+    "loader.js": "^4.0.1",
+    "rsvp": "^3.3.2"
   },
   "dependencies": {
     "ember-cli-babel": "^5.1.6"