Use non-member to test restriction by GitLab user

This uses no authentication and the email address
`non_member_user@non_member_user.com` to test the
option to restrict commits by author email to GitLab users.

Previously it used the email address `root@gitlab.com`, which _is_ a
user on GitLab.com.

qa/qa/resource/repository/push.rb

@@ -60,13 +60,13 @@ module QA
 
             repository.use_lfs = use_lfs
 
-            username = 'GitLab QA'
+            name = 'GitLab QA'
             email = 'root@gitlab.com'
 
             if user
               repository.username = user.username
               repository.password = user.password
-              username = user.name
+              name = user.name
               email = user.email
             end
 
@@ -75,7 +75,7 @@ module QA
             end
 
             @output += repository.clone
-            repository.configure_identity(username, email)
+            repository.configure_identity(name, email)
 
             @output += repository.checkout(branch_name, new_branch: new_branch)
 

qa/qa/specs/features/ee/browser_ui/3_create/repository/push_rules_spec.rb

@@ -23,7 +23,6 @@ module QA
               push_rules.fill_commit_message_rule(@needed_phrase_limitation)
               push_rules.fill_deny_commit_message_rule(@deny_message_phrase_limitation)
               push_rules.check_prevent_secrets
-              push_rules.check_restrict_author
               push_rules.check_deny_delete_tag
               push_rules.click_submit
             end
@@ -81,11 +80,6 @@ module QA
             error: Regexp.escape('File name id_rsa was blacklisted by the pattern id_rsa$'))
         end
 
-        it 'restricts commits by user' do
-          expect_error_on_push(file: standard_file, user: @root,
-            error: Regexp.escape("Author '#{@root.email}' is not a member of team"))
-        end
-
         it 'restricts removal of tag' do
           tag = Resource::Tag.fabricate_via_api! do |tag|
             tag.project = @project
@@ -98,6 +92,31 @@ module QA
         end
       end
 
+      describe 'with commits restricted by author email to existing GitLab users' do
+        before do
+          prepare
+
+          Page::Project::Settings::Repository.perform do |repository|
+            repository.expand_push_rules do |push_rules|
+              push_rules.check_restrict_author
+              push_rules.click_submit
+            end
+          end
+        end
+
+        it 'rejects non-member users' do
+          non_member_user = Resource::User.new.tap do |user|
+            user.username = ''
+            user.password = ''
+            user.name = 'non_member_user'
+            user.email = 'non_member_user@non_member_user.com'
+          end
+
+          expect_error_on_push(file: standard_file, user: non_member_user,
+            error: Regexp.escape("Author '#{non_member_user.email}' is not a member of team"))
+        end
+      end
+
       describe 'with commits restricted to verified emails' do
         before do
           prepare