Add acceptance testing for 4.2 and 4.4

[baurmatt]

Test current version of Zabbix.

[baurmatt]

Travis for Ubuntu 16.04:

Error: Unable to connect to PostgreSQL server! (:5432)

  Error: /Stage[main]/Postgresql::Server::Service/Postgresql_conn_validator[validate_service_is_running]/ensure: change from 'absent' to 'present' failed: Unable to connect to PostgreSQL server! (:5432)

I think the error is unrelated because:

1. Works on my machine ;)
2. Happens on master as well
3. Works for all other OSs

[alexjfisher]

@baurmatt Build on master has been fixed. Wanna rebase? (and take the opportunity to fix the commit message spelling mistake)