Update test-unit requirement from = 3.3.6 to = 3.3.7 (#2195)

Updates the requirements on [test-unit](https://github.com/test-unit/test-unit) to permit the latest version.
- [Release notes](https://github.com/test-unit/test-unit/releases)
- [Commits](test-unit/test-unit@3.3.6...3.3.7)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Gemfile.lock

@@ -44,7 +44,7 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    test-unit (3.3.6)
+    test-unit (3.3.7)
       power_assert
     timecop (0.9.2)
     unicode-display_width (1.7.0)
@@ -60,7 +60,7 @@ DEPENDENCIES
   rake (= 13.0.1)
   rubocop (= 1.1.0)
   simplecov (= 0.17.1)
-  test-unit (= 3.3.6)
+  test-unit (= 3.3.7)
   timecop (= 0.9.2)
   yard (= 0.9.25)
 

faker.gemspec

@@ -34,7 +34,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency('rake', '13.0.1')
   spec.add_development_dependency('rubocop', '1.1.0')
   spec.add_development_dependency('simplecov', '0.17.1')
-  spec.add_development_dependency('test-unit', '3.3.6')
+  spec.add_development_dependency('test-unit', '3.3.7')
   spec.add_development_dependency('timecop', '0.9.2')
   spec.add_development_dependency('yard', '0.9.25')
 end