Remove Add Cluster button from clusters/index

app/views/projects/clusters/_tabs.html.haml

@@ -14,5 +14,3 @@
       = link_to project_clusters_path(@project), class: "js-all-tab" do
         = s_("ClusterIntegration|All")
         %span.badge= @all_count
-  .nav-controls
-    = link_to s_("ClusterIntegration|Add cluster"), new_project_cluster_path(@project), class: "btn btn-success btn-add-cluster disabled has-tooltip js-add-cluster", title: s_("ClusterIntegration|Multiple clusters are available in GitLab Entreprise Edition Premium and Ultimate")

spec/features/projects/clusters_spec.rb

@@ -35,10 +35,6 @@ feature 'Clusters', :js do
       expect(page).to have_selector('.gl-responsive-table-row', count: 2)
     end
 
-    it 'user sees a disabled add cluster button ' do
-      expect(page).to have_selector('.js-add-cluster.disabled')
-    end
-
     it 'user sees navigation tabs' do
       expect(page.find('.js-active-tab').text).to include('Active')
       expect(page.find('.js-active-tab .badge').text).to include('1')