Remove test settings button, enhance Save changes button, include Integrations bundle

app/views/projects/services/_form.html.haml

+- content_for :page_specific_javascripts do
+  = webpack_bundle_tag('integrations')
+
 .row.prepend-top-default.append-bottom-default
   .col-lg-3
     %h4.prepend-top-0
@@ -6,15 +9,17 @@
 
     %p= @service.description
   .col-lg-9
-    = form_for(@service, as: :service, url: namespace_project_service_path(@project.namespace, @project, @service.to_param), method: :put, html: { class: 'form-horizontal' }) do |form|
+    = form_for(@service, as: :service, url: namespace_project_service_path(@project.namespace, @project, @service.to_param), method: :put, html: { class: 'gl-show-field-errors form-horizontal js-integration-settings-from' }) do |form|
       = render 'shared/service_settings', form: form, subject: @service
       .footer-block.row-content-block
-        = form.submit 'Save changes', class: 'btn btn-save'
+        %button.btn.btn-save{ type: 'submit' }
+          %i.fa.fa-spinner.fa-spin.hidden.js-btn-spinner{ "aria-hidden" => true }
+          %span.js-btn-label
+            Save changes
          
         - if @service.valid? && @service.activated?
           - unless @service.can_test?
             - disabled_class = 'disabled'
             - disabled_title = @service.disabled_title
 
-          = link_to 'Test settings', test_namespace_project_service_path(@project.namespace, @project, @service), class: "btn #{disabled_class}", title: disabled_title
         = link_to "Cancel", namespace_project_settings_integrations_path(@project.namespace, @project), class: "btn btn-cancel"