Bump to version 1.0.3
Bump to version 1.0.3

Version 1.0.3 includes the following bug fixes:

* fixed an encoding issue with message unpacking
* remove unused dependency pubsub

nicoe/i3ipc-python,xenomachina/i3ipc-python,acrisci/i3ipc-python,chrsclmn/i3ipc-python