add debug output for sidekiq on staging

lib/travis/api/v3/extensions/sidekiq.rb

@@ -0,0 +1,20 @@
+require 'sidekiq'
+
+module Travis::API::V3
+  module Extensions
+    module Sidekiq
+      module Client
+        def push(item)
+          Travis.logger.info("Sidekiq job scheduled: #{item.inspect}") if debug_push?
+          super
+        end
+
+        def debug_push?
+          Travis.env == 'development'.freeze or Travis.env == 'staging'.freeze
+        end
+      end
+
+      ::Sidekiq::Client.send(:prepend, Client)
+    end
+  end
+end