Merge pull request #356 from ruby-i18n/dependabot/bundler/test-unit-3.7.7

Bump test-unit from 3.7.3 to 3.7.7

Author: movermeyer

Gemfile.lock

@@ -134,7 +134,7 @@ GEM
     rubyzip (3.2.2)
     semver2 (3.4.2)
     stringio (3.2.0)
-    test-unit (3.7.3)
+    test-unit (3.7.7)
       power_assert
     thor (1.5.0)
     thread_safe (0.3.6)