Port parameters

[krikoon73]

By default, the library doesn't handle a specific port :

var uri = this.proto + '://' + this.host + this.url

Maybe change with :

var uri = this.proto + '://' + this.host + ':' + this.port + this.url;

And add a default value :

this.port = (typeof opts.port === 'string') ? opts.port : '443'