Bump mocha from 2.4.2 to 2.4.3

Bumps [mocha](https://github.com/freerange/mocha) from 2.4.2 to 2.4.3.
- [Changelog](https://github.com/freerange/mocha/blob/main/RELEASE.md)
- [Commits](freerange/mocha@v2.4.2...v2.4.3)

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

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

Gemfile.lock

@@ -204,7 +204,7 @@ GEM
       capybara
       minitest (~> 5.0)
       rake
-    mocha (2.4.2)
+    mocha (2.4.3)
       ruby2_keywords (>= 0.0.5)
     msgpack (1.7.2)
     mutex_m (0.2.0)