refactor buildcancellation worker

lib/travis/api/workers/build_cancellation.rb

@@ -10,19 +10,8 @@ module Travis
       # do we need to name the queue here? we didn't do this in Admin. We passed this info in the procfile
       sidekiq_options queue: build_cancellations
 
-      attr_accessor :data
-
       def perform(data)
-        @data = data
-        if payload
-          service.run
-        else
-          Travis.logger.warn("The #{type} payload was empty and could not be processed")
-        end
-      end
-
-      def service
-        @service ||= Travis.service(:cancel_build, data)
+        Travis.service(:cancel_build, data).run
       end
     end
   end