fixes #40

This is a very simple to fix to the problem with ports where it
will occaisonally throw an error:

• race condition when used simultaneously across multiple processes hoodiehq-archive/node-ports#4

The fix is to catch the error and use port 3000. Not great, but should
handle some cases where this was a problem.

An alternate fix to try would be to try fetching the port again, probably
in a loop (with some limit), in hopes of getting a value from ports.