Bash completion for flags

[mabelzhang]

🎉 New feature

Part of gazebosim/gz-tools#1
Used together with gazebosim/gz-tools#87

Summary

Bash completion, installation, tests.

Test it

$ . install/share/gz/gz1.completion
$ ign launch -
--force-version  --help           --verbose        --versions       -h               -v

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[chapulina]

LGTM!

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (ign-launch2@0c6eaa5). Click here to learn what that means.
The diff coverage is n/a.

@@              Coverage Diff               @@
##             ign-launch2     #167   +/-   ##
==============================================
  Coverage               ?   30.24%           
==============================================
  Files                  ?        3           
  Lines                  ?      734           
  Branches               ?        0           
==============================================
  Hits                   ?      222           
  Misses                 ?      512           
  Partials               ?        0           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0c6eaa5...2937d5d. Read the comment docs.