Extract the "environment" context manager for tests
Configure the root logger, not just a logger named "root"...
`test_handler_propagation` was based on incorrect assumptions

`propagation` refers to _message_ propagation (i.e. bubble up the logger
tree) rather than _config_ propagation ("inheritance" if you will) so an
arbitrary logger won't have root handlers; messages sent to it will just
reach the root logger (barring any intercepts) and be handled by its
handlers.
Absolute imports for Python 3 compatibility
Merge pull request #15 from doismellburning/feature/root-logger-fix

Configure the root logger, not just a logger named "root"...