Bump mocha from 3.5.3 to 5.0.4

Bumps [mocha](https://github.com/mochajs/mocha) from 3.5.3 to 5.0.4.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](mochajs/mocha@v3.5.3...v5.0.4)

Signed-off-by: dependabot[bot] <support@dependabot.com>

package.json

@@ -51,7 +51,7 @@
     "eslint-plugin-ember": "^5.0.0",
     "eslint-plugin-node": "^5.2.1",
     "loader.js": "^4.2.3",
-    "mocha": "^3.0.0"
+    "mocha": "^5.0.4"
   },
   "keywords": [
     "ember-addon",