Bump mocha from 2.6.1 to 2.7.0

Bumps [mocha](https://github.com/freerange/mocha) from 2.6.1 to 2.7.0.
- [Changelog](https://github.com/freerange/mocha/blob/main/RELEASE.md)
- [Commits](freerange/mocha@v2.6.1...v2.7.0)

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

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

Gemfile.lock

@@ -173,7 +173,7 @@ GEM
     mini_mime (1.1.5)
     mini_portile2 (2.8.8)
     minitest (5.25.4)
-    mocha (2.6.1)
+    mocha (2.7.0)
       ruby2_keywords (>= 0.0.5)
     msgpack (1.7.5)
     net-http (0.6.0)