add: repository update destroy webhook

app/views/projects/webhooks/edit.json.jbuilder

@@ -0,0 +1,11 @@
+json.id @webhook.id 
+json.(@webhook, :id, :http_method, :content_type, :url, :secret, :last_status, :is_active)
+json.type @webhook.hook_task_type
+json.create_time Time.at(@webhook.created_unix).strftime("%Y-%m-%d %H:%M:%S")
+event = JSON.parse(@webhook.events)
+json.branch_filter event["branch_filter"]
+if event["send_everything"]
+  json.events event["events"].keys
+else 
+  json.events event["events"].select{|k, v| v}.keys
+end