Merge branch 'release/0.15'

api/funkwhale_api/users/factories.py

api/funkwhale_api/users/middleware.py

...funkwhale_api/users/migrations/0008_auto_20180617_1531.py

...funkwhale_api/users/migrations/0009_auto_20180619_2024.py

api/funkwhale_api/users/models.py

api/funkwhale_api/users/serializers.py

api/funkwhale_api/users/views.py

api/tests/common/test_fields.py

api/tests/common/test_serializers.py

api/tests/conftest.py

api/tests/manage/test_serializers.py

api/tests/manage/test_views.py

api/tests/music/test_tasks.py

api/tests/test_import_audio_file.py

api/tests/users/test_middleware.py

api/tests/users/test_models.py

api/tests/users/test_views.py

deploy/nginx.conf

docs/importing-music.rst

docs/installation/index.rst