Bump minitest from 5.25.1 to 5.25.4

Bumps [minitest](https://github.com/minitest/minitest) from 5.25.1 to 5.25.4.
- [Changelog](https://github.com/minitest/minitest/blob/master/History.rdoc)
- [Commits](https://github.com/minitest/minitest/compare/v5.25.1...v5.25.4)

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

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -51,7 +51,7 @@ GEM
       thor (>= 0.19, < 2.0)
     logger (1.6.1)
     mini_portile2 (2.8.8)
-    minitest (5.25.1)
+    minitest (5.25.4)
     minitest-hooks (1.5.2)
       minitest (> 5.3)
     mocha (2.6.1)