Merge branch 'fix-group-hooks-mock' into 'master'

Fix group hooks mock

Closes #4519

See merge request gitlab-org/gitlab-ee!3982

features/steps/group_hooks.rb

@@ -41,8 +41,10 @@ class Spinach::Features::GroupHooks < Spinach::FeatureSteps
   end
 
   step 'I click test hook button' do
+    WebMock.enable!
     stub_request(:post, @hook.url).to_return(status: 200)
     click_link 'Test'
+    WebMock.disable!
   end
 
   step 'I click test hook button with invalid URL' do