Create a set of test data for w.org/themes

Moved from https://meta.trac.wordpress.org/ticket/4993

> The themes team is blocked in part by missing data they can test on locally.
You can set up the environment in VVV, but when you go to http://wordpressorg.test/themes/, and log in the admin, there are not themes packages.

See original ticket for more description and comments

Related #141 

