US#12: Roles per project
Fixing tests and documentation
SmallFix: Fixing issue with site admin project links
Initial integration with appear-in
Adding talky support
Changed travis settings
US #57: Task #90: Create a blocked abstract model
Bug#132: Adding bulk of tasks
Smallfix: Change wrong related name of the field assigned_to in the Task model
Now a user story can be assigned
US 41: Task #100: Add fields to activate and desactivate kanban and backlog
US #50: Return neighbors when fetching an US/Issue

The response for an UserStory/Issue now contains:

{
    ...
    "neighbors": {
        "previous": {
            "id": ...,
            "ref": ...,
            "subject": ...
        },
        "next": {
            ... same as above
        }
    }
}

If there's a neighbor missing the response will contain the empty dict {}:

{
    ...
    "neighbors": {
        "previous": {},
        ...
    }
}

Neighbors are looked up applying the same filters defined in the
corresponding ViewSets and the same ordering defined in those filters or
ultimately, in the model's meta. In other words, using the same params
you use to filter the object list, can be used to filter the neighbors
when fetching the object's details.