Add Missing Type Annotations

[tcfranks]

resolves #25
submitted for review / comment

Note: in thermal_printer_2168.py the function warm_up accepts an argument "heat_time" and never makes use of it...should it?

[tcfranks]

@tekktrik , @FoamyGuy - um, local pylint disagrees with the automated run or I wouldn't have submitted - can you interpret the error for me?

[tekktrik]

It's a warning about code duplication - it's a pylint warning describing that code is extremely similar and could probably be refactored. I don't think that's necessary here so we should just disable the warning. I'll get back to you on how to do so shortly, or may just push the change myself if that's okay, let me know

[tcfranks]

either way is fine.....I was able to get local pylint (run on entire directory) to duplicate the error but not suppress it. That was a learning point for me on running on multiple files. but evidently, via quick Google, "# pylint: disable=duplicate-code" isn't something that is (easily?) implemented, so, whatever you think is best....

[tekktrik]

The trick is to disable it either in .pylintrc (which disables it for pylint) or in .pre-commit-config.yaml (which disables it for the pre-commit hook of pylint). I think the latter is preferable because 1) it won't get lost in the other disables if this ever does get refactored and B) it seems like something we'd rather silence in pre-commit as opposed to pylint directly. It's how we've done this in the past. You can see that last commit for how I applied the fix!

[tekktrik]

Note: in thermal_printer_2168.py the function warm_up accepts an argument "heat_time" and never makes use of it...should it?

No, let's keep it - I think it's worth preserving this change with the scope of this PR. We make API-breaking changes in another one.

[tcfranks]

resubmitted for review with reviewer requested changes

[tekktrik]

Feedback below

[tcfranks]

resubmitted for review with reviewer comments

[tcfranks]

resubmitted with 1 change

[tekktrik]

Thanks!