chore(package): update eslint-plugin-ember to version 7.6.0

Closes #60

Author: greenkeeper[bot]

package.json

@@ -52,7 +52,7 @@
     "ember-source": "~3.10.0",
     "ember-source-channel-url": "^2.0.1",
     "ember-try": "^1.2.1",
-    "eslint-plugin-ember": "^6.2.0",
+    "eslint-plugin-ember": "^7.6.0",
     "eslint-plugin-node": "^9.0.1",
     "loader.js": "^4.7.0",
     "qunit-dom": "^0.8.4"