The documentation for the `state` field is not very clear.
It says possible values are "installed, uninstalled" and default value is "present"
The examples below alow uses `present` and `absent`.
This patch uses "absent" and "present" instead of "installed" and "uninstalled"
Moreover, this is consistent with other packaging modules, like homebrew itself
Indrajit Raychaudhuri
Enric Lluelles
Jasper Lievisse Adriaanse
Greg DeKoenigsberg
Toshio Kuratomi
Brian Coca
Julien Vey
Michael DeHaan