Proposal: concurrent checks running on workflow

[marccampbell]

Instead of running all checks sequentially (part of the issue in #23), the CLI could show all of the actions and each check that needs to run, with a spinner on each, indicating what's happening and what's still running...

job: build-proaction
  step: actions/setup-go@v1
    outdated-action:    ✓
    unstable-github-ref: ✓

each step should complete before moving to the next, replacing the content on the screen with the next step.

[marccampbell]

Not all can be executed concurrently -- some checks build on the output of others. For example, the unstable-github-ref check might recommend a change from a v1.0 to a v1.0.3 tag, while the outdated might bump to a v2 tag.