Build & publish packages on Github actions

[takluyver]

In preparation for another release.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 71.09%. Comparing base (8ce52fd) to head (356e37d).
Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #44   +/-   ##
=======================================
  Coverage   71.09%   71.09%           
=======================================
  Files           9        9           
  Lines         557      557           
=======================================
  Hits          396      396           
  Misses        161      161           

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[tmichela]

I usually prefer to publish only on release tags, see for example EXtra but that's up to you

LGTM

[takluyver]

Thanks! I'm happy enough treating any tag as a release, since I still don't use Github releases consistently 😕 🦕 . This is working for EXtra-data & EXtra-geom.