configurable database backend

.env.sample

 DEBUG=True
 DISABLE_IPV4_BLOCK=False
+DATABASE_BACKEND='django.db.backends.postgresql'
+DATABASE_NAME='app'
 ALLOWED_HOSTS=.localhost, .ipv6.work
 AUTH_LDAP_SERVER_URI=ldap://<ldap_host>
 AUTH_LDAP_BIND_DN=cn=admin,dc=example,dc=com

ipv6work/settings.py

@@ -102,8 +102,8 @@ WSGI_APPLICATION = 'ipv6work.wsgi.application'
 
 DATABASES = {
     'default': {
-        'ENGINE': 'django.db.backends.sqlite3',
-        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
+        'ENGINE': config('DATABASE_BACKEND', default='django.db.backends.sqlite3'),
+        'NAME': config('DATABASE_NAME', default=os.path.join(BASE_DIR, 'db.sqlite3')),
     }
 }