Fixed yeoman generator tests and refactored setup using promises

Change-Id: Ib70fa2fcf6e6d549f6f73d0f13f33edc07699c1c
diff --git a/views/ngXosLib/generator-xos/package.json b/views/ngXosLib/generator-xos/package.json
index 0098496..b86287a 100644
--- a/views/ngXosLib/generator-xos/package.json
+++ b/views/ngXosLib/generator-xos/package.json
@@ -9,6 +9,7 @@
   "author": "Matteo Scandolo",
   "license": "ISC",
   "dependencies": {
+    "bluebird": "^3.4.1",
     "yeoman-generator": "^0.21.1"
   },
   "files": [