Feature/add ssl support

Enable SSL support on the TCP transport, tested & working against logstash-12.1 input configured like this:

    tcp {
      type => "tcp-plain"
      host => "0.0.0.0"
      port => "5959"
      ssl_enable => true
      codec =>   oldlogstashjson { }
      ssl_verify => false
      ssl_cacert => '/etc/logstash/cacert.pem'
      ssl_cert => '/etc/logstash/logstash.crt'
      ssl_key => '/etc/logstash/logstash.key'
    }


Configuration in beaver is simple:

    [beaver]
    tcp_host = remote_logstash_server.localnet
    tcp_port = 5959
    tcp_ssl_enabled = True