Small fix in readme, added debian package help on readme and added suppo...

Hi! 

Please pardon if my perl skills are old :-)

Fixes on readme:
- Object was created inside $api but all other examples used $zabbix as object var.
- Added extra info regading Moo.pm and JSON.pm

Fixes on code:
- Added non required option "invalidssl" which if exist will allow connection to https servers with invalid certificates.