chore(package): update ember-ajax to version 3.1.1

Closes #14

Author: greenkeeper[bot]

package.json

@@ -21,7 +21,7 @@
   "devDependencies": {
     "body-parser": "^1.15.2",
     "broccoli-asset-rev": "^2.4.5",
-    "ember-ajax": "^2.4.1",
+    "ember-ajax": "^3.1.1",
     "ember-cli": "2.11.1",
     "ember-cli-app-version": "^2.0.0",
     "ember-cli-babel": "^5.1.7",