fix(requirements): Specific about Django version.
fix(requirements): Specific about Django version.

Django 1.9 is available, and was taken into use by e.g Travis as the
version just needed to be greater than 1.8.0. However, it seems things
have changed in 1.9 and currently the app is not compatible with 1.9.
Hence, using specific version 1.8.4.

jokimies/django-pj-feedreader,jokimies/django-pj-feedreader,jokimies/django-pj-feedreader,jokimies/django-pj-feedreader