Add simple test type that allows you to specify when buttons are pressed

[virtuald]

This is the most common type of simplistic test one might want, I imagine. The primary usefulness I think would be exercising all your stuff, so you can be sure that they don't have syntax errors. Adding an additional function that gets called to check it is nice, but should be optional. Something like.. hm. I don't really know what this looks like. Maybe:

# port, button number?
release = (1, 1)
fire = (1,2)

# time, button to press (defaults to pressing for 0.2s)
tests = [
  (1.0, release),
  (2.0, fire),
  .. 
]

run_button_test(tests)

@sarosenb you should do this.