[CHORE] Changing dependency to ember-source

Addresses review comments

Author: rajasegar

manifest.json

@@ -84,7 +84,7 @@
   },
   "cp-property-map-codemod": {
     "versions": {
-      "ember-cli": "3.9.0-beta.1"
+      "ember-source": "3.9.0-beta.1"
     },
     "projectOptions": ["app", "addon"],
     "nodeVersion": "6.0.0",