added a styling stage to check the styles first

[kailuowang]

before committing to run the full build.

[codecov-io]

Codecov Report

Merging #2752 into master will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2752      +/-   ##
==========================================
- Coverage   95.34%   95.32%   -0.02%     
==========================================
  Files         363      363              
  Lines        6782     6783       +1     
  Branches      290      290              
==========================================
  Hits         6466     6466              
- Misses        316      317       +1

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[kailuowang]

It makes it possible for each module to define which scala version to release on (based on their own crossScalaVersions), also simplifies the build here.

[LukaJCB]

Great idea 👍

[kailuowang]

@ceedubs , do you happen to have time to take a look? You mentioned something about Travis stage not working in some way. This run seems fine to me. Maybe they fixed it?

[ceedubs]

👍.

The reason that I didn't go down this path is that I think that it slightly slows down the overall build time (because the longest-running tasks can't start right away). But that may be worth it to have builds fail quickly for trivial errors.

[kailuowang]

Yes. That occurred to me as well. Since all cats PRs/branch build share the same concurrent VMs, I think it's worth the little delay to free up VMs for other PRs.