robot: if the Alvik is switched off when it is running, the I2C stops working

If the robot is switched off, the Alvik library is not able to detect any I2C sensor (like the modulino Leds).

A possible solution is:

upload the dev branch of [Arduino Alvik](https://github.com/arduino-libraries/Arduino_Alvik)
upload the dev branch of [Alvik-mpy](https://github.com/arduino/arduino-alvik-mpy)