[Envoy] Allow custom port in envoy

[DevDavido]

Specifying custom ports to connect to a remote server via SSH would be a useful addition to Envoy.
Example:
@servers(['web' => 'user@192.168.1.1:5678'])

[thannaske]

Good idea.
This should be pretty easy to implement. Maybe you could fork the laravel/envoy repo and start a pull request? In the end you need to specify -p $port at this line: https://github.com/laravel/envoy/blob/master/src/RemoteProcessor.php#L47

Furthermore there are some changes in the configuration and configuration parsing that need to be made.

[rajdeut]

PR created... laravel/envoy#132