code: def start(environment, opts):
      
      environment.require_data()
  
      if environment.fully_running():
          print 'Already running at {0}'.format(environment.web_address())
          return
  
      reload_(environment, opts)
docs: Create containers and start serving environment
  
  Usage:
    datacats start [-b] [--site-url SITE_URL] [-p|--no-watch] [-s NAME]
                   [-i] [--syslog] [--address=IP] [ENVIRONMENT [PORT]]
    datacats start -r [-b] [--site-url SITE_URL] [-s NAME] [--syslog]
                   [-i] [--address=IP] [ENVIRONMENT]
  
  Options:
    --address=IP          Address to listen on (Linux-only)
    -b --background       Don't wait for response from web server
    --no-watch            Do not automatically reload templates and .py files on change
    -i --interactive      Calls out to docker via the command line, allowing
                          for interactivity with the web image.
    -p --production       Start with apache and debug=false
    -s --site=NAME        Specify a site to start [default: primary]
    --syslog              Log to the syslog
    --site-url SITE_URL   The site_url to use in API responses. Defaults to old setting or
                          will attempt to determine it. (e.g. http://example.org:{port}/)
  
  ENVIRONMENT may be an environment name or a path to an environment directory.
  Default: '.'