fix(package): update ember-cli-sass to version 9.0.1

Closes #13

Author: greenkeeper[bot]

package.json

@@ -57,7 +57,7 @@
     "ember-cli-bootstrap-4": "^0.5.9",
     "ember-cli-htmlbars": "^2.0.1",
     "ember-cli-htmlbars-inline-precompile": "^1.0.0",
-    "ember-cli-sass": "^7.0.0",
+    "ember-cli-sass": "^9.0.1",
     "ember-concurrency": "^0.8.19",
     "ember-font-awesome": "^4.0.0-rc.3",
     "ember-light-table": "^1.12.2",