For those of you who wants to use your own username instead of outernet, you may use these commands:
sudo adduser your_username_here -D
sudo passwd -a MD5 your_username_here
sudo addgroup your_username_here sudo
and if you are brave enough you can lock the outernet user:
sudo passwd -l outernet
NB: This sometimes kicks you out of SSH everytime you try to login with the new user, but not always - I think this might be a bug somewhere in Skylark ?
Alternatively you may just change the default password for the outernet user, or just leave it as it is after you have added your own user.