This was missing in x86 builds and we don't have a test verifying the
crontabs themselves, so it was never caught. It would be better to
verify those, but that would mean async testing which could result in
very slow builds or other issues.
Fixes#5
As handy as cross-build-start is for building arm images on an x86
machine, it actually causes building to fail when on an arm machine.
Added an or statement to allow it to build on my rpi as well as my
laptop.
