This is a library to flash LEDs in a non-blocking way.
The library allows creation of Flasher objects, which take a pin to flash, and a duty cycle, in the form of on-time and off-time.
The run function checks whether it's time to do something with the LED, and should be run once per loop. These calls are non-blocking. The update function may be used to change the blink rate of a running Flasher object.