Fix database backend returned as bytes wont work with Python 3.5.2+ & Django==1.11

[rafahsolis]

ine 211, in getitem
backend = load_backend(db['ENGINE'])
File "/home/rafa/.virtualenvs/djangosecure3/lib/python3.5/site-packages/django/db/utils.py", line 134, in load_backend
raise ImproperlyConfigured(error_msg)
django.core.exceptions.ImproperlyConfigured: b'django.db.backends.sqlite3' isn't an available database backend.
Try using 'django.db.backends.XXX', where XXX is one of:
'mysql', 'oracle', 'postgresql', 'sqlite3'
Error was: No module named "b'django"