Async/await all the things

[JasonEtco]

Back with another PR - this time, switching some Promises code out for async/await. The only real benefit is readability, but it does help a good amount.

I've also done some light cleanup in log.js, swapping out var for const and replacing the for...of loop with Array.map. Since the end goal is an array of formatting strings, the result should be the same with a little less verbosity - let me know how you feel about that change, or if you prefer it the old way!

[bnb]

Tried running locally and getting an error with array.map:

[JasonEtco]

Whoops, fixed in 8c9b46e @bnb! Thanks for checking!

[bnb]

Merged ❤️