Add enjoy-core as dependency to better refactor the code

Author: jsteinbeck

package.json

@@ -14,6 +14,7 @@
     "databus": "^1.0.1",
     "eases": "^1.0.8",
     "easy-ajax": "^1.0.0-final.1512141736",
+    "enjoy-core": "^1.0.1",
     "howler": "^1.1.29",
     "string-dict": "^1.0.0",
     "transform-js": "^1.1.0-final.1512141547",