Add support for viewing parallel test runs to CI plugin

[jabrown85]

Why

In order to better support parallel test runs going GA, we wanted to add a way to visually see the node statuses usingci:info and ci:last.

This means that the commands ci:info and ci:lastinclude now the --node flag.

• Publish a changelog entry for this?

We also updated ci:run and ci:rerun to output the first node in parallel run cases for now.

Bonus points:

• Migrated to oclif ci:info, ci:last, ci:run and ci:rerun
• Added tests for command we previously had untested 🐼

What's next

• Add support to visually show all test nodes executing when parallel test runs is enabled

What's next after next

• Migrate to oclif

  • config-get
  • config-index
  • config-set
  • debug
  • index
  • open

• Remove

  • migrate-manifest

Edited by @raulb

[raulb]

@jabrown85 Thanks for helping me to bring it to the finish line! Since both of us worked on this PR, it'd might be helpful if we could get a review by the @heroku-cli team if possible!

In the meantime, I'll go ahead and approve 😎