Local subdomains config

### /etc/hosts
127.0.0.1       localhost
127.0.0.1       local.dev.io
127.0.0.1       adminsub.local.dev.io
127.0.0.1       u3sub.local.dev.io
...

### local.py
# SECURE_HSTS_INCLUDE_SUBDOMAINS = True
# DOMAIN_NAME = "local.dev.io"
SESSION_COOKIE_DOMAIN = ".local.dev.io"