test runner similar to testrepository - doc

 Stestr stands for Slim/Super Test Repository. It is a fork of the
 testrepository that concentrates on being a dedicated test runner for Python
 projects. The generic abstraction layers which enabled testr to work with any
 subunit emitting runner are gone. Stestr hard codes python-subunit-isms into
 how it works. The code base is also designed to try and be explicit, and to
 provide a Python API that is documented and has examples.
 .
 While stestr was originally forked from testrepository it is not 100%
 backwards compatible with testrepository. At a high level the basic concepts
 of operation are shared between the 2 projects but the actual usage between
 the 2 is not exactly the same.
 .
 This package contains the documentation.