fix(package): update ember-cli-htmlbars to version 4.0.7

Closes #9

Author: greenkeeper[bot]

package.json

@@ -55,7 +55,7 @@
   "dependencies": {
     "ember-cli-babel": "^6.6.0",
     "ember-cli-bootstrap-4": "^0.5.9",
-    "ember-cli-htmlbars": "^2.0.1",
+    "ember-cli-htmlbars": "^4.0.7",
     "ember-cli-htmlbars-inline-precompile": "^1.0.0",
     "ember-cli-sass": "^7.0.0",
     "ember-concurrency": "^0.8.19",