Log Message:
py-pexpect: updated to 4.7.0

Version 4.7
* The :meth:.pxssh.login method now no longer requires a username if an ssh
  config is provided and will raise an error if neither are provided.
* The :meth:.pxssh.login method now supports providing your own ssh
  command via the cmd parameter.
* :class:.pxssh now supports the use_poll parameter which is passed into \ 
:meth:.pexpect.spawn
* Minor bug fix with ssh_config.
* :meth:.replwrap.run_command now has async support via an async_ parameter.
* :meth:.pexpect.spawn will now read additional bytes if able up to a buffer limit.