chore(package): update ember-source to version 3.19.0

Closes #11

Author: greenkeeper[bot]

package.json

@@ -52,7 +52,7 @@
     "ember-moment": "7.6.0",
     "ember-resolver": "^4.5.0",
     "ember-simple-auth": "^1.1.0",
-    "ember-source": "^2.11.0",
+    "ember-source": "^3.19.0",
     "eonasdan-bootstrap-datetimepicker": "^4.17.46",
     "express": "^4.13.4",
     "glob": "^7.1.2",