use milliseconds instead to support smaller boards

[rhooper]

Addresses #62

[caternuson]

Looks good. One suggested cosmetic code tweak. Sort of a deja vu feeling - I did pretty much these same mods yesterday, made this easy to review :)

Tested on Trinket M0 with a basic blink, and it works.

[rhooper]

Hmm - Tested with 6.x and get No long integer support

[rhooper]

@caternuson can you look again?

[caternuson]

I tested with 5.3.1. But seeing same with 6.0 alpha 2. I'm guessing this a bug in current 6.x build. I've asked the devs. Stay tuned....

Adafruit CircuitPython 6.0.0-alpha.2 on 2020-07-23; Adafruit Trinket M0 with samd21e18
>>> import time
>>> dir(time)
['__name__', 'localtime', 'mktime', 'monotonic', 'monotonic_ns', 'sleep', 'struct_time', 'time']
>>> time.monotonic()
90.376
>>> time.monotonic_ns()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NotImplementedError: No long integer support
>>> 

[caternuson]

So...sounds like it's a behavior change for 6.x. Instead of not having the methods present, they will be present but throw an exception.

So I guess the import logic needs to change accordingly.

[caternuson]

Related:
adafruit/circuitpython#2812

[rhooper]

The latest version in this branch should work on Trinket M0 on 5.3.1 and 6.0.0-latest (6.0.0-alpha.0-556-g3197c579e-dirty)

[caternuson]

@rhooper OK, grabbed latest. Yep, works now.

[rhooper]

@caternuson Looking for an approval to merge