Prepare 0.13.1 release

Release 0.13.0

Merge pull request CZ-NIC#426 from rohe/release.0.12.0

Release 0.12.0

Minor bug fix release.

Major refactoring and bug fix release.

New import path and internal fixes.

More work on the federation stuff

Making federated client request and handling such a request now works.

Fix provider_config redirect with relative URL

Release version