Update bundled_gems

gems/bundled_gems

@@ -1,5 +1,5 @@
 # gem-name version-to-bundle repository-url [optional-commit-hash-to-test-or-defaults-to-v-version]
-minitest 5.14.3 https://github.com/seattlerb/minitest
+minitest 5.14.4 https://github.com/seattlerb/minitest
 power_assert 2.0.0 https://github.com/ruby/power_assert
 rake 13.0.3 https://github.com/ruby/rake
 test-unit 3.4.0 https://github.com/test-unit/test-unit 3.4.0