1.2.0

Changes

• Added constants for session related flags under ssh2.session.
• Added ssh2.session.Session.flag function for enabling/disabling session flags like compression support.
• Added ssh2.session.userauth_keyboardinteractive_callback for authentication using Python callback function,
  for example for Oauth and other two-factor (2FA) or more factor authentication. Thanks @MattCatz .
• ssh2.sftp_handle.SFTPHandle.closed is now a public property indicating whether ssh2.sftp_handle.SFTPHandle.close
  was called on a SFTPHandle or not.
• Added ssh2.channel.Channel.signal function for sending signals over SSH to an open channel - #221
• Added ssh2.session.Session.direct_streamlocal_ex for creating Channel objects tunneling a local UNIX socket
  via the remote host to a third party - #40
• Added new libssh2 error codes under ssh2.error_codes, equivalent Python exceptions under ssh2.exceptions
  and updated error code handling for all functions.
• Removed deprecated libssh2 ssh2.channel.Channel functions receive_window_adjust, handle_extended_data
  and ignore_extended_data.
• Removed deprecated libssh2 ssh2.session.Session functions startup, scp_recv and scp_send.

Packaging

• Removed Windows Python 3.7 wheel builds.
• OSX binary wheels now use embedded libssh2 rather than brew package.