Log Message:
py-asyncssh: updated to 1.11.1

Release 1.11.1:
Switched to using PBKDF2 implementation provided by PyCA, replacing a much \ 
slower pure-Python implementation used in earlier releases.
Improved support for file-like objects in process I/O redirection, properly \ 
handling objects which don’t support fileno() and allowing both text and \ 
binary file objects based on whether they have an ‘encoding’ member.
Changed PEM parser to be forgiving of trailing blank lines.
Updated documentation to note lack of support in OpenSSH for send_signal(), \ 
terminate(), and kill() channel requests.
Updated unit tests to work better with OpenSSH 7.6.
Updated Travis CI config to test with more recent Python versions.