[WIP] views refactoring
[WIP] clened
[WIP] fixing flake errors
[WIP] changed order
fixed flake errors
Merge branch 'develop' into debt/234-split-views

Conflicts:
	src/ralph_assets/views/invoice_report.py
	src/ralph_assets/views/transition.py
speed up licence admin view
Hotfix - slots field is not shown when model category attribute ``is_blade`` is True
small changes after review
more than pep8
small changes after review
Merge branch 'debt/234-split-views' of github.com:ar4s/ralph_assets into debt/234-split-views

Conflicts:
	src/ralph_assets/views/asset.py
data_import instead of xls_import
Merge pull request #311 from ar4s/feature/raw-fields-in-licence-admin

Speed up licence admin view
Merge pull request #312 from quamilek/hotfix/slots-in-dc

Hotfix - slots field not shown when model is blade server
Merge pull request #306 from ar4s/debt/234-split-views

Split views
Merge branch 'develop' into budget-info

Conflicts:
	src/ralph_assets/views_search.py
fixed saving *coa_oem_os*; rm redundant url; tests factories improved; fixed UserFactory's parent class;