v0.18.0 - Fancy `Server` `__repr__`

Fancy Server repr

• Server: Add __repr__, __eq__, set socket_path if none set.

  Before (0.17 and below):

  <libtmux.server.Server object at ...>

  New __repr__ (0.18+):

  Server(socket_name=test)

  Server(socket_path=/tmp/tmux-1000/default)

  by @tony in #463

Full Changelog: v0.17.2...v0.18.0