Bump mocha from 2.5.0 to 2.7.1 (#1235)

Bumps [mocha](https://github.com/freerange/mocha) from 2.5.0 to 2.7.1.
- [Changelog](https://github.com/freerange/mocha/blob/main/RELEASE.md)
- [Commits](freerange/mocha@v2.5.0...v2.7.1)

---
updated-dependencies:
- dependency-name: mocha
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -324,7 +324,7 @@ GEM
     mini_mime (1.1.5)
     mini_portile2 (2.8.8)
     minitest (5.25.2)
-    mocha (2.5.0)
+    mocha (2.7.1)
       ruby2_keywords (>= 0.0.5)
     msgpack (1.7.3)
     multi_json (1.15.0)