Support non-interactive continuous-delivery system use cases

[tjaneczko]

This PR adds the following to the gh-release CLI:

• A --noconfirm flag for skipping the confirmation prompt (modeled after Arch Linux' pacman's --noconfirm)
• The ability to read an authentication token from the GH_RELEASE_GITHUB_API_TOKEN environment variable

These two features combined allow for gh-release to be used in continuous-delivery systems (like Jenkins) where user interaction is not possible. It also allows these systems to work with multiple GitHub APIs (i.e. github.com and a self-hosted Enterprise GitHub) by simply swapping out the token environment variable.

Resolves #75

[ungoldman]

Hi @tjaneczko, thanks for this PR!

Only one comment: I'm more a fan of the -y or --yes convention mentioned in the original issue (#75), which is a common convention for npm and node userland, as opposed to noconfirm, which sounds like something more specific to Arch Linux's pacman package manager.

Otherwise looks great!

Are you willing to update to use yes with a y alias instead of noconfirm?

[tjaneczko]

Sure thing! Will switch back to using --yes with a y alias. Thanks for the review!

[tjaneczko]

@ungoldman should be all set for another look!

[ungoldman]

📦 3.3.0 🚀