Add better access to Github

[jirhiker]

Is your feature request related to a problem? Please describe.
Need a better way of authenticating users for pushing to github for dvc

Describe the solution you'd like
I think OAuth is the way to go? Pychron launches, checks if credentials set, if not starts to oauth process, opens a browser window, etc...

[jirhiker]

use https://github.com/cli/cli as part of the stack.

for installation user needs to install git, gh, and edm. the installer should then run gh auth login