Add spec/frontend/ to frontend roulette

lib/gitlab/danger/helper.rb

@@ -106,13 +106,13 @@ module Gitlab
 
         %r{\A(ee/)?app/(assets|views)/} => :frontend,
         %r{\A(ee/)?public/} => :frontend,
-        %r{\A(ee/)?spec/javascripts/} => :frontend,
+        %r{\A(ee/)?spec/(javascripts|frontend)/} => :frontend,
         %r{\A(ee/)?vendor/assets/} => :frontend,
         %r{\A(jest\.config\.js|package\.json|yarn\.lock)\z} => :frontend,
 
         %r{\A(ee/)?app/(?!assets|views)[^/]+} => :backend,
         %r{\A(ee/)?(bin|config|danger|generator_templates|lib|rubocop|scripts)/} => :backend,
-        %r{\A(ee/)?spec/(?!javascripts)[^/]+} => :backend,
+        %r{\A(ee/)?spec/(?!javascripts|frontend)[^/]+} => :backend,
         %r{\A(ee/)?vendor/(?!assets)[^/]+} => :backend,
         %r{\A(ee/)?vendor/(languages\.yml|licenses\.csv)\z} => :backend,
         %r{\A(Dangerfile|Gemfile|Gemfile.lock|Procfile|Rakefile|\.gitlab-ci\.yml)\z} => :backend,

spec/lib/gitlab/danger/helper_spec.rb

@@ -217,6 +217,7 @@ describe Gitlab::Danger::Helper do
       'app/views/foo'        | :frontend
       'public/foo'           | :frontend
       'spec/javascripts/foo' | :frontend
+      'spec/frontend/bar'    | :frontend
       'vendor/assets/foo'    | :frontend
       'jest.config.js'       | :frontend
       'package.json'         | :frontend
@@ -225,6 +226,7 @@ describe Gitlab::Danger::Helper do
       'ee/app/assets/foo'       | :frontend
       'ee/app/views/foo'        | :frontend
       'ee/spec/javascripts/foo' | :frontend
+      'ee/spec/frontend/bar'    | :frontend
 
       'app/models/foo' | :backend
       'bin/foo'        | :backend