Remove checks trigger from server migration flow
Change test prefix to delete snapshots as well as test images
Fix crossdomain requests

- add @crosdomain to all endpoints;
- make default value for 'Cross-Domain-Allow-Origin: *';
- add default allowed headers ('Accept' and 'Content-Type');
- force creation of 'OPTIONS' method on all endpoints;
Force creation of 'novanetwork' network in setup

This network is required for further servers creation.
Add tests for security group migration tasks
Remove unused import from server.py
Ensure straigh argument order for image tasks
PEP8 fix
Merge branch 'newenv-fixes'

Fixes found spinning up new development environment.
Merge remote-tracking branch 'origin/master' into context

Conflicts:
	pumphouse/tasks/image.py
	pumphouse/tasks/server.py