Improve the version file information

This adds the version information (and the git tag), e.g.

>>> import pyfstat
>>> pyfstat.__version__
'1.3: (CLEAN) 4fdfc02 2020-01-22 08:40:17 +1100'

added 1 commit

• ae60804c - Run black

Compare with previous version

@GregAshton This is basically a copy of what bilby does, so should be fine, right? Want me to approve it, or keep it open through the migration?

I checked it and it ran all okay. I'm happy if you either want to approve and merge, or delay.

merged

mentioned in commit 4f7a96d4