Bump mocha from 2.0.2 to 2.1.0

Bumps [mocha](https://github.com/freerange/mocha) from 2.0.2 to 2.1.0.
- [Changelog](https://github.com/freerange/mocha/blob/main/RELEASE.md)
- [Commits](freerange/mocha@v2.0.2...v2.1.0)

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

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

Gemfile.lock

@@ -298,7 +298,7 @@ GEM
       rake
     mini_mime (1.1.2)
     minitest (5.20.0)
-    mocha (2.0.2)
+    mocha (2.1.0)
       ruby2_keywords (>= 0.0.5)
     msgpack (1.6.0)
     multi_json (1.15.0)