mention 'minikube logs' for debugging start failures

cmd/minikube/cmd/start.go

@@ -341,7 +341,7 @@ func runStart(cmd *cobra.Command, args []string) {
 		fmt.Println("Starting cluster components...")
 		if err := k8sBootstrapper.StartCluster(kubernetesConfig); err != nil {
 			glog.Errorln("Error starting cluster: ", err)
-			cmdutil.MaybeReportErrorAndExit(err)
+			cmdutil.MaybeReportErrorAndExit(fmt.Errorf("%s\nYou may be able to failure logs using: 'minikube logs'\n"))
 		}
 	} else {
 		fmt.Println("Machine exists, restarting cluster components...")