drop EOL FreeBSD and OpenBSD

[Dan33l]

This Pull Request (PR) fixes the following issues

Fixes #199

[decibelhertz]

I use this module on FreeBSD and Linux. This does not simply remove EOL BSDs, it removes support for BSD. Why not edit metadata.json to contain { "operatingsystem": "FreeBSD", "operatingsystemrelease": [ "11","12" ] }, (etc), which are not EOL and do work with rspec-puppet-tests? Your Hiera config could then look like:

snmp::package_name: 'net-mgmt/net-snmp'
snmp::service_config_dir_path: '/usr/local/etc/snmp'
snmp::service_config_dir_perms: '0755'
snmp::service_config_dir_owner: 'root'
snmp::service_config_dir_group: 'wheel'
snmp::service_config: '/usr/local/etc/snmp/snmpd.conf'
snmp::service_config_perms: '0755'
snmp::service_name: 'snmpd'
snmp::snmpd_options: 'd'
snmp::var_net_snmp: '/var/net-snmp'
snmp::varnetsnmp_perms: '0600'
snmp::varnetsnmp_owner: 'root'
snmp::varnetsnmp_group: 'wheel'
snmp::client_package_name: 'net-mgmt/net-snmp'
snmp::client_config: '/usr/local/etc/snmp/snmp.conf'
snmp::trap_service_config: '/usr/local/etc/snmp/snmptrapd.conf'
snmp::trap_service_name: 'snmptrapd'
snmp::snmptrapd_options:
snmp::snmptrapd_package_name: 

[bastelfreak]

@decibelhertz are you able to provide a PR for FreeBSD 11/12? I'm happy to add it back if the tests succeed.