Adds tabs to environments list

app/views/projects/environments/index.html.haml

@@ -5,6 +5,19 @@
 %div{ class: container_class }
   - if can?(current_user, :create_environment, @project) && !@environments.blank?
     .top-area
+      %ul.nav-links
+        %li{class: ('active' if @scope.nil?)}
+          = link_to project_environments_path(@project) do
+            Availabe
+            %span.badge.js-avaibale-environments-count
+              = number_with_delimiter(@available_environments_count)
+              
+        %li{class: ('active' if @scope == 'stopped')}
+          = link_to project_environments_path(@project, scope: :stopped) do
+            Stopped
+            %span.badge.js-stopped-environments-count
+              = number_with_delimiter(@stopped_environments_count)
+
       .nav-controls
         = link_to new_namespace_project_environment_path(@project.namespace, @project), class: 'btn btn-create' do
           New environment