Usage:
  hit create [<numWorkers> <reward> <duration>]
  hit extend <HITid> [--assignments <number>] [--expiration <time>]
  hit expire (--all | <HITid> ...)
  hit delete (--all | <HITid> ...)
  hit list [--active | --reviewable]
  hit help

'hit' is used with the following subcommands:
  create      Post a new HIT with the given number of
  	      assignments, reward amount, and duration. Will be posted either
	      live to Amazon Mechanical Turk or to the Worker Sandbox depending
  	      upon your current mode. 'hit create' can also be run
  	      interactively by entering the command without parameters.
  extend      Extend an existing HIT by a number of assignments and/or amount
  	      of time before the HIT expires.
  expire      Expire one or more existing HITs, or expire all HITs using
  	      the '--all' flag.
  delete      Delete of one or more existing HITs, or delete of all HITs
    	      using the '--all' flag.
  list	      List all HITs, or list all active or reviewable HITs using the
              provided flags.
  help	      Display this screen.
