Check for requisites

[bstillman]

We should add a check for xtrabackup, perl-Digest-MD5, mail, etc. Maybe this should be a setup/configuration script.

[hroest]

@jpfeuffer it seems like now your test with regards to type safety doesnt work any more -- I can revert this and add the namespace-enum test separately, what do you think?

[jpfeuffer]

Yes separate tests would work great I think. Thank you!

[timosachsenberg]

@jpfeuffer is this ready to merge?

[jpfeuffer]

This precedes CI and needs to be updated to run the tests.

And looking at our comments, it sounds like CI might fail.

[jpfeuffer]

@timosachsenberg Now you can see the failures. Once they are fixed, we can merge.

[timosachsenberg]

thanks!