Bump test-unit from 3.6.2 to 3.6.3

Bumps [test-unit](https://github.com/test-unit/test-unit) from 3.6.2 to 3.6.3.
- [Release notes](https://github.com/test-unit/test-unit/releases)
- [Commits](test-unit/test-unit@3.6.2...3.6.3)

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

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

Gemfile.lock

@@ -114,7 +114,7 @@ GEM
       hashery (~> 2.0)
       ruby-rc4
       ttfunk
-    power_assert (2.0.3)
+    power_assert (2.0.4)
     public_suffix (6.0.1)
     racc (1.8.0)
     rainbow (3.1.1)
@@ -131,7 +131,7 @@ GEM
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    test-unit (3.6.2)
+    test-unit (3.6.3)
       power_assert
     timers (4.3.5)
     ttfunk (1.8.0)