Use remotes directly rather than devtools

[jimhester]

While using docker container frees you from worrying about a lot of the dependency headaches of travis, you don't really need all of devtools installed.

Instead I would recommend using R CMD build to build the package, remotes to do the dependency installation, and if you want pretty check output the rcmdcheck package.

[maxheld83]

thanks @jimhester that's great advice.

I actually haven't thought through how to best use GitHub actions for packages yet; I just threw the main.workflow for this package together real quickly.

Hope to get to that soon, but I thought I'd start with the easier *down projects first.

Anyway, I'm very grateful for any advice or directions you might have for how to best leverage GitHub actions.

[maxheld83]

this is part of #2