Whenever group_by=infrastructure is used, raise a ConnectorException
if a group is not found.
Merge pull request #1 from alvarolopez/split

Split
Merge branch 'master' of https://github.com/orviz/achus

Conflicts:
	reporter.py
Modify README's title.
Raise exception whenever a group mapping is not found, while grouping
by 'infrastructure'.
Update README's usage.
Make classes inherit from objects
Start using oslo.cfg to manage configuration

It is now possible to use oslo.cfg to manage the GE collector
configuration.
Load report configuration from YAML file
Added setup.py and initial CLI to generate reports
Rename connector to collector everywhere