chore(package): update @ember/optional-features to version 1.1.0

Closes #16

Author: greenkeeper[bot]

package.json

@@ -30,7 +30,7 @@
     "ember-cli-htmlbars": "^3.0.1"
   },
   "devDependencies": {
-    "@ember/optional-features": "^0.7.0",
+    "@ember/optional-features": "^1.1.0",
     "broccoli-asset-rev": "^3.0.0",
     "ember-cli": "~3.10.1",
     "ember-cli-code-coverage": "^0.4.2",