Quarantine flaky tests

See issues:
https://gitlab.com/gitlab-org/quality/nightly/issues/72
https://gitlab.com/gitlab-org/quality/staging/issues/19
https://gitlab.com/gitlab-org/quality/staging/issues/29

qa/qa/specs/features/browser_ui/1_manage/ee_group/group_level_project_template_spec.rb

@@ -2,7 +2,8 @@
 require 'securerandom'
 
 module QA
-  context :manage do
+  # Failure issue: https://gitlab.com/gitlab-org/quality/nightly/issues/72
+  context 'Manage', :quarantine do
     describe 'Group level project template' do
       let(:files) do
         [

qa/qa/specs/features/browser_ui/2_plan/ee_epic/create_edit_delete_epic_spec.rb

 # frozen_string_literal: true
 
 module QA
-  context 'Plan' do
+  # Failure issue: https://gitlab.com/gitlab-org/quality/staging/issues/19
+  context 'Plan', :quarantine do
     describe 'Epics Creation' do
       before(:all) do
         Runtime::Browser.visit(:gitlab, Page::Main::Login)

qa/qa/specs/features/browser_ui/2_plan/ee_epic/promote_issue_to_epic_spec.rb

 # frozen_string_literal: true
 
 module QA
-  context 'Plan' do
+  # Failure issue: https://gitlab.com/gitlab-org/quality/staging/issues/29
+  context 'Plan', :quarantine do
     describe 'promote issue to epic' do
       let(:issue_title) { "My Awesome Issue #{SecureRandom.hex(8)}" }