Merge lp://staging/~msabramo/testrepository/add_logging into lp://staging/~testrepository/testrepository/trunk

testrepository/setuptools_command.py: Add logging

to aid in debugging and testing.

I submitted the same change to pbr as https://review.openstack.org/89203

The interesting thing is that with this change in both pbr and testrepository I can see that there is weird behavior when one runs `python setup.py testr` -- methods for distutils commands defined in both are called.

```
 ❯ .tox/cover/bin/python setup.py testr --coverage
INFO:pbr.testr_command:imported
INFO:pbr.testr_command:initialize_options called
INFO:testrepository.setuptools_command:imported
running testr
INFO:testrepository.setuptools_command:initialize_options called
INFO:testrepository.setuptools_command:finalize_options called
INFO:testrepository.setuptools_command:run called
INFO:testrepository.setuptools_command:_coverage_before called
INFO:testrepository.setuptools_command:os.environ['PYTHON'] = 'coverage run --source jenkins-job-builder --parallel-mode'
INFO:testrepository.setuptools_command:_run_testr called
running=OS_STDOUT_CAPTURE=${OS_STDOUT_CAPTURE:-1} OS_STDERR_CAPTURE=${OS_STDERR_CAPTURE:-1} OS_LOG_CAPTURE=${OS_LOG_CAPTURE:-1}
```