Update ember-data to the latest version

Author: Jonas Metzener

package.json

@@ -45,7 +45,7 @@
     "ember-code-snippet": "^2.2.0",
     "ember-component-css": "^0.3.5",
     "ember-concurrency": "^0.8.16",
-    "ember-data": "^2.18.0",
+    "ember-data": "^3.4.0",
     "ember-fetch": "^4.0.2",
     "ember-fetch-adapter": "^0.4.2",
     "ember-href-to": "^1.15.1",