chore(package): update ember-cli-htmlbars to version 4.2.0

Closes #92

Author: greenkeeper[bot]

package.json

@@ -40,7 +40,7 @@
     "ember-cli": "~3.4.3",
     "ember-cli-dependency-checker": "^3.0.0",
     "ember-cli-eslint": "^4.2.3",
-    "ember-cli-htmlbars": "^3.0.0",
+    "ember-cli-htmlbars": "^4.2.0",
     "ember-cli-htmlbars-inline-precompile": "^1.0.3",
     "ember-cli-inject-live-reload": "^1.8.2",
     "ember-cli-qunit": "^4.3.2",