chore(package): update ember-data to version 3.12.2

Closes #21

Author: greenkeeper[bot]

package.json

@@ -36,7 +36,7 @@
     "ember-cli-sri": "^2.1.0",
     "ember-cli-test-loader": "^1.1.0",
     "ember-cli-uglify": "^1.2.0",
-    "ember-data": "^2.9.0",
+    "ember-data": "^3.12.2",
     "ember-data-github": "0.3.0",
     "ember-export-application-global": "^1.0.5",
     "ember-load-initializers": "^0.6.3",