Show python version with slapos --version

$ slapos --version
slapos 1.7.7 (Python 3.9.2)
4 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed SlapOS-Master.UnitTest-Master

01:56:20

passed SlapOS.Eggs.UnitTest-Master.Python2

passed SlapOS.Eggs.UnitTest-Master.Python3

00:15:08

passed SlapOS.Eggs.UnitTest-Master.Python2

00:14:57