Bump mocha from 6.1.4 to 7.0.0 (#562)

Bumps [mocha](https://github.com/mochajs/mocha) from 6.1.4 to 7.0.0.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](mochajs/mocha@v6.1.4...v7.0.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package.json

@@ -64,7 +64,7 @@
     "eslint-plugin-ember": "^6.5.1",
     "eslint-plugin-node": "^11.0.0",
     "loader.js": "^4.7.0",
-    "mocha": "^6.0.0",
+    "mocha": "^7.0.0",
     "mocha-eslint": "^5.0.0",
     "mocha-only-detector": "^1.0.0",
     "qunit-dom": "^0.9.2"