Open Stack

Hey,

I think it's time we retired os-testr. It is already effectively unmaintained
and we made a concerted effort some cycles ago to migrate all projects to
stestr. I think it's time we finally closed that out. For any projects still
using os-testr, stestr effectively provides a drop-in replacement.

I'll propose patches to do this shortly. Please let me know if anyone has any
concerns about this course of action.

Cheers,
Stephen