[VOTE] Migrate our main repositories to GitHub

[Joern Kottmann]

Hello all,

lets decide here if we want to move our main repository, currently
hosted at Apache to GitHub instead. This will make our process a bit
easier because we can eliminate one remote from our workflow.

     [ ] +1 Migrate all repositories to GitHub
     [ ] -1 Do not migrate,  because...

Thanks,
Jörn