chore(package): update ember-cli-babel to version 7.20.2

Closes #64

Author: greenkeeper[bot]

package.json

@@ -22,7 +22,7 @@
     "ember-chrome-devtools": "^0.2.0",
     "ember-cli": "^2.18.0",
     "ember-cli-app-version": "^3.0.0",
-    "ember-cli-babel": "^6.7.0",
+    "ember-cli-babel": "^7.20.2",
     "ember-cli-dependency-checker": "^2.0.0",
     "ember-cli-deploy": "^1.0.2",
     "ember-cli-deploy-build": "^1.1.1",