clarify logs and gitignore and skipping vendor from now on

Former-commit-id: c8b61b58379d768f04e1593c2a77cf429407cf62

handlers/handler.go

@@ -26,7 +26,7 @@ func (h *Handler) Run() error {
 		case j := <-h.Jobs:
 			go func(key string) {
 				if err := h.Job(key); err != nil {
-					log.Println(err)
+					log.Println("[h.Run]", err)
 				}
 			}(j.Key)
 		}