Remove test fixtures completely

[skip ci]
Add factory boy to requirements
Start using factory boy

Doing a lot better with factory boy than with model mommy

[skip ci]
Factory fixtures for "blog" tests

[skip ci]
Factory fixures for "tickets" app

[skip ci]
New factories and drop "defaults" from Body's QSM get_or_create method
Use factories with "queue" tests

[skip ci]
Celery 3.1 will be the last version to support Python 2.6
Use factories in website tests
Filter out inboxes that have no user

This only happens when a user to deleted, therefore this inbox *shouldn't* receive emails
Test factories: BinaryField won't handle Unicode

Missed this as SQLite is unfazed by your human Unicodes
Clean up Liberation tests

PostgreSQL doesn't give predictable IDs, not that we should rely on them anyway
Merge branch 'factory-boy-issue-37'

Completely remove JSON fixtures and replace them with Factory Boy. A lot
more flexible and tests are twice as quick.

Closes #35
Closes #37
Added default flake8 config

Closes Inboxen/infrastructure#73
Fix various issues with blog

* blog wasn't showing pagination links
* blog urls contained extra "blog"
Merge branch 'master' into deploy