Cucumber Reports #164

To enable cucumber-node users to share reports with Cucumber Reports, we should add some equivalent to the --publish option from other Cucumber implementations.

The best way would probably be to model it as a custom reporter (as we've done with the html and junit ones) where the internals do the comms with the reports service and the output is the returned banner from the service. We should suggest users direct to this to stderr so they see it but can still use a regular reporter for stdout.