Quarantine flaky specs

Related to:

- https://gitlab.com/gitlab-org/gitlab-ce/issues/60270
- https://gitlab.com/gitlab-org/gitlab-ce/issues/60271
- https://gitlab.com/gitlab-org/gitlab-ce/issues/60272
- https://gitlab.com/gitlab-org/gitlab-ce/issues/60273

Signed-off-by: Rémy Coutable <remy@rymai.me>

spec/features/issues/filtered_search/dropdown_milestone_spec.rb

@@ -139,7 +139,7 @@ describe 'Dropdown milestone', :js do
       expect_filtered_search_input_empty
     end
 
-    it 'fills in the milestone name when the milestone is partially filled' do
+    it 'fills in the milestone name when the milestone is partially filled', :quarantine do
       filtered_search.send_keys('v')
       click_milestone(milestone.title)
 

spec/features/labels_hierarchy_spec.rb

@@ -21,7 +21,7 @@ describe 'Labels Hierarchy', :js, :nested_groups do
   end
 
   shared_examples 'assigning labels from sidebar' do
-    it 'can assign all ancestors labels' do
+    it 'can assign all ancestors labels', :quarantine do
       [grandparent_group_label, parent_group_label, project_label_1].each do |label|
         page.within('.block.labels') do
           find('.edit-link').click

spec/features/merge_request/user_creates_image_diff_notes_spec.rb

@@ -113,7 +113,7 @@ describe 'Merge request > User creates image diff notes', :js do
           create_image_diff_note
         end
 
-        it 'shows indicator and avatar badges, and allows collapsing/expanding the discussion notes' do
+        it 'shows indicator and avatar badges, and allows collapsing/expanding the discussion notes', :quarantine do
           indicator = find('.js-image-badge', match: :first)
           badge = find('.user-avatar-link .badge', match: :first)
 

spec/features/projects/wiki/user_creates_wiki_page_spec.rb

@@ -43,7 +43,7 @@ describe "User creates wiki page" do
         expect(page).to have_content("Create Page")
       end
 
-      it "shows non-escaped link in the pages list", :js do
+      it "shows non-escaped link in the pages list", :js, :quarantine do
         fill_in(:wiki_title, with: "one/two/three-test")
 
         page.within(".wiki-form") do