Bump config from 5.5.0 to 5.5.1 (#254)

Bumps [config](https://github.com/rubyconfig/config) from 5.5.0 to 5.5.1.
- [Release notes](https://github.com/rubyconfig/config/releases)
- [Changelog](https://github.com/rubyconfig/config/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubyconfig/config/commits)

---
updated-dependencies:
- dependency-name: config
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -34,7 +34,7 @@ GEM
       thor (~> 1.0)
     coderay (1.1.3)
     concurrent-ruby (1.2.3)
-    config (5.5.0)
+    config (5.5.1)
       deep_merge (~> 1.2, >= 1.2.1)
     connection_pool (2.4.1)
     crass (1.0.6)