chore(package): update eslint-plugin-ember to version 6.6.0

Closes #72

Author: greenkeeper[bot]

package.json

@@ -50,7 +50,7 @@
     "ember-resolver": "^4.0.0",
     "ember-simple-auth": "^1.4.0",
     "ember-source": "~2.18.0",
-    "eslint-plugin-ember": "^5.0.0",
+    "eslint-plugin-ember": "^6.6.0",
     "loader.js": "^4.2.3",
     "semantic-ui-ember": "^2.0.1"
   },