Change default admin info

[thecaffiend]

Currently the AMI creates a passwordless admin user for TLJH. Would be great if we could lock this down moire and controll this info from the deployment repo. Something like:

• install TLJH in the AMI without an admin user
• on first boot of the EC2 instance, put a deployment controlled config file in there with admin info controlled from the deployer (encrypted passwords and such)
• restart TLJH so the config takes
• go from there.