Set log level to default value
Set log level to default value

Instead of setting the log level hard coded to INFO just let the used
logger module decide which level is the default. Otherwise a usage
of this module will change the log level globally to INFO which is not
the default for the python logger module (see
http://hg.python.org/cpython/file/2.7/Lib/logging/__init__.py#l1490)

Change-Id: I75a0517564e6829dfc1451c77da888548ad2219c
Closes-bug: 1320841

openstack/oslotest,openstack/oslotest