1.0.11: Fixed deadlock when child process reads from stdin

- Fixed a deadlock that can occur when the child process tries to read
  from the standard input

- The deadlock occurs because jobson provides no standard input to child
  processes, but keeps the standard input open. This causes child processes
  to deadlock indefinitely when 'read'ing from stdin

- This fix makes jobson 'close' the standard input of any child process
  at launch time. If any child process attempts to read from the standard
  input they'll read 0 bytes then stop

- See https://github.com/adamkewley/jobson/issues/67 for more info

- Thanks to @Russel88 for finding this bug!