Add port to endpoint if passed custom port

Closes issue #168.

Passes all tests except for:

```
  ✖ 2 of 58 tests failed:

  1)  test .request() to get ACL (?acl):
     Error: socket hang up
      at createHangUpError (http.js:1409:15)
      at CleartextStream.socketCloseListener (http.js:1459:23)
      at CleartextStream.EventEmitter.emit (events.js:95:17)
      at tls.js:616:10
      at process._tickCallback (node.js:415:13)

  2)  test .deleteMultiple():
     Error: socket hang up
      at createHangUpError (http.js:1409:15)
      at CleartextStream.socketCloseListener (http.js:1459:23)
      at CleartextStream.EventEmitter.emit (events.js:95:17)
      at tls.js:616:10
      at process._tickCallback (node.js:415:13)
```

Those fail on master for me as well, so I'm not sure what's up with them.