Add Slack notification support

static/css/quay.css

@@ -4573,6 +4573,13 @@ i.hipchat-icon {
   height: 16px;
 }
 
+i.slack-icon {
+  background-image: url(/static/img/slack.ico);
+  background-size: 16px;
+  width: 16px;
+  height: 16px;
+}
+
 .external-notification-view-element {
   margin: 10px;
   padding: 6px; 

static/js/app.js

@@ -1141,6 +1141,24 @@ quayApp = angular.module('quay', quayDependencies, function($provide, cfpLoading
             'title': 'Notification Token'
           }
         ]
+      },
+      {
+        'id': 'slack',
+        'title': 'Slack Room Notification',
+        'icon': 'slack-icon',
+        'fields': [
+          {
+            'name': 'subdomain',
+            'type': 'string',
+            'title': 'Slack Subdomain'
+          },
+          {
+            'name': 'token',
+            'type': 'string',
+            'title': 'Token',
+            'help_url': 'https://{subdomain}.slack.com/services/new/outgoing-webhook'
+          }
+        ]
       }
     ];