Vagrant development environment

This was originally developed by Abhiram Chintangal <abhiram.chintangal@gmail.com> with a bunch of fixups
and the merge-request from Oliver Baumann <baumanno@cip.ifi.lmu.de> and some additional cleanups and
fixes from Karsten Loesing <karsten.loesing@gmx.net> and meejah

"vagrant up" should give you a development environment running at https://weather.dev if you followed the
instructions.