Just installed frambuesa 3 and a username and password is required. Havent come across this in the docs. Raspbian default usernames and passwords not working. Google searches keep crossing out "frambuesa".
Just solved my own problem, and I thought it might help someone (it was really hard getting these, i wonder why!
username: erlepassword: holaerle
It's explained in there http://docs.erlerobotics.com/brains/erle-brain-3/getting_started/ssh