chore(package): update ember-a11y-testing to version 0.4.2

Closes #9

Author: greenkeeper[bot]

package.json

@@ -27,7 +27,7 @@
     "bootstrap-sass": "^3.3.7",
     "broccoli-asset-rev": "^2.4.2",
     "coveralls": "^2.11.15",
-    "ember-a11y-testing": "0.2.1",
+    "ember-a11y-testing": "0.4.2",
     "ember-ajax": "^2.0.1",
     "ember-bootstrap": "1.0.0-alpha.10",
     "ember-cli": "~2.8.0",