message: travis failing shrug
  `home/travis/.arduino15/packages/esp8266/hardware/esp8266/2.6.0/cores/esp8266/debug.h:8:26: error: '::printf' has not been declared`
diff: */
  #include <WiFiManager.h> // https://github.com/tzapu/WiFiManager
  #include <time.h>
  +#include <stdio.h>
  #define USEOTA
  // enable OTA
  #ifdef USEOTA
  +#include <ESPmDNS.h>
  #include <WiFiUdp.h>
  #include <ArduinoOTA.h>
  #endif
  