When calling client.API, allow for optional port to be assigned in en…

…dpointRequest which is then used in the buildrequest.

This is to allow for environments that sit behind corporate firewalls or proxies that have strict environments were HTTPs request must have port 443 assigned during request (unlike the current default request which is empty).

lib/client.js

@@ -58,6 +58,10 @@ function Client (globalRequest) {
     request.host = endpointRequest.host || globalRequest.host
     request.method = endpointRequest.method
 
+    if (endpointRequest.port) {
+      request.port = endpointRequest.port
+    }
+
     // build URL
     request.path = !isEmpty(endpointRequest.queryParams)
       ? buildPath(endpointRequest.path, endpointRequest.queryParams)