This simple library allows control of switch reluctance motors such
as those found in hard disks. It provides varying degrees of precision
assuming three phases.
Library also supports rudimentary speed control which allows programmers
to control motor speed without resorting to usage of `delay`. This is done
through setting speed measured in revolutions per minute and calling
`motor_step` or `motor_step_backward` frequently. State of pins will be
updated only after specific time has passed. Speed control does take into
account sequence sizes, so no additional calculation is needed.