added http_timeout as a command line option for runserver (#387)
added http_timeout as a command line option for runserver (#387)

* added http_timeout as a comand line option for runserver

* possible improvement for input param management

* explicitly set the default http_timeout in add_argument

raphael-boucher/channels,Coread/channels,Krukov/channels,Krukov/channels,andrewgodwin/django-channels,django/channels,raiderrobert/channels,Coread/channels,linuxlewis/channels,andrewgodwin/channels