check_pakfire

• dropped support for Python 2.x
• fixed several errors which prevented the plugin to work with Python 3.x (see also issue #19)
• cleaned-up code

This is a re-release from 23.04.2019

• added options -n and --need-reboot to check for required reboots
• fixed a bug where -C and -W were not evaluated properly (see also issue #17)