Django-defender

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- Add redispy 3.2.0 compatibility [nrth]

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- Remove Python 3.3 [fr0mhell]
- Remove Django 1.8-1.10 [fr0mhell]
- Add Celery v4 [fr0mhell]
- Update travis config [fr0mhell]
- Update admin URL [fr0mhell]

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- Add new setting ``DEFENDER_GET_USERNAME_FROM_REQUEST_PATH`` for control how username is accessed from request [andrewshkovskii]
- Add new argument ``get_username`` for ``decorators.watch_login`` to propagate ``get_username`` argument to other utils functions calls done in ``watch_login`` [andrewshkovskii]

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- Add 2 new setting variables for more granular failure limit control [williamboman]
- Add ssl option when instantiating StrictRedis [mjrimrie]
- Send signals when blocking username or ip [williamboman]

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- Remove mockredis as install requirement, make only test requirement [blueyed]

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- Fix regex in 'unblock_username_view' to handle special symbols [ruthus18]
- Fix django requires version for 1.11.x [kencochrane]
- Remove hiredis dependency [ericbuckley]
- Correctly get raw client when using django_redis cache. [cburger]
- Replace django.core.urlresolvers with django.urls For Django 2.0 [s-wirth]
- Add username kwarg for providing username directly rather than via callback arg [williamboman]
- Only use the username if it is actually provided [cobusc]