Optimistic Concurrency Control first approach
Updating current version in presave instead of doing it in the post_save method
Avoiding race conditions in pre_save
Fixing tests
Merge pull request #49 from taigaio/concurrency-control

Optimistic Concurrency Control first approach
Adding archived user stories feature and enabling API filtering
Merge pull request #50 from taigaio/archived-us

Adding archived user stories feature and enabling API filtering
Implement tags using pg arrays
tags to pg array migrations
Re-applying migration in conflict
Bugfix
create_membership factory function
Idiomatic code snippet
Removing duplicated code
Add more licenses agreements to the tests module
Adding is_staff to users
Add more licenses agreements to the tests.unit module
Update AUTHORS
Add more licenses agreements to the tests.integration module
Support parametrized urls in the api root view

Generating the api root view was failing because urls like this

`issues/(?P<issue_id>\\d+)/voters`

cannot be reversed without the appropriate params.