Bugfix: Reload version attr in OCC
Fixing milestone serializer, adding duplicated name validation
Project api should return all roles
Required estimated-start/end dates for milestones
Merge pull request #53 from taigaio/bugfixes

Bugfixes
Add request to requirements
Add full_name_display to the user serializer
Fixing admin
Return user's gravatar if has no photo set

If the user has no photo set use her gravatar image if available
otherwise use the default avatar image defined in
`settings.DEFAULT_AVATAR_URL`
wip - taiga services