Allows adding scripts to a directory to be executed before backups and
after restorating. This can allow backing up a mysql dump or something.

Using these could (and probably does) break verify checks

Fixes #8

Try to fix build error on ARM

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

This reverts commit 137d32c575.

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.

Should simulate an S3 test

Updated to latest boto for AWS S3 EU compatibility

Fixes #1

If needed, it can be added via opt args