added AssetEnvType model class + used it in device & added to admin view
better names for AssetEnvType & added migration file
added new table ServiceCatalog & used it in discovery.device
flake8 ready ;P
service_catalog inherited from cmdb.ci
better import
added utils files with object factories (for tests) & device lookups
rm unused lookup DeviceEnvironment
added factory-boy to setup.py
flake8 ready
better docstring
review impr.
Merge pull request #992 from xliiv/ser-env-fields

service & environment fields
fixed get_item_url bug
hasattr replaced with getattr
Merge pull request #994 from xliiv/ser-env-fields

fixed get_item_url bug
Added 'SyncFieldMixin' + some additional logic in order to keep selected
fields in sync between 'Device' and 'Asset' models.
Added 'service catalog' and 'environment' fields to the 'device info' form.
flake8
Code review improvements (making syncing mechanism more flexible).