fix: upgrade ember-cli from 3.12.0 to 3.16.0 (#21)

Snyk has created this PR to upgrade ember-cli from 3.12.0 to 3.16.0.

See this package in NPM:
https://www.npmjs.com/package/ember-cli

See this project in Snyk:
https://app.snyk.io/org/nodeshift-starters/project/255abb11-a6e1-48a1-87b7-513da98dce3a?utm_source=github&utm_medium=upgrade-pr

ember/client/package.json

@@ -21,7 +21,7 @@
     "broccoli-asset-rev": "^3.0.0",
     "ember-ajax": "^5.0.0",
     "ember-auto-import": "~1.5.2",
-    "ember-cli": "~3.12.0",
+    "ember-cli": "~3.16.0",
     "ember-cli-app-version": "^3.2.0",
     "ember-cli-babel": "^7.18.0",
     "ember-cli-dependency-checker": "^3.1.0",