I followed the install instructions up to single node, and it failed to start saying it couldn't contact rabbitMQ.
So ran the extra steps to set up rabbitMQ (and mongoDB, just in case), and then my single node would start. Should those extra steps be required? The documentation implies not.
Looks like I am not the first person to notice this, here is an issue from 5 months ago:
The docs imply rabbitmq and mongodb are not needed. They are first mentioned in the section about clustering.