Hello, i'm currently going through OdinProject course and they've got installation process
linked to your http://installfest.railsbridge.org/installfest/linux page.

On the 3.1 step you're proposing command

curl -L get.rvm.io | bash -s stable

and on my Ubuntu it does something but with errors. (GPG signature verification failed and etc.)

In the official instruction there is a first step

Before any other step install mpapis public key (might need gpg2) (see security)

gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3

And only after that 3.1 command worked properly. Could you add it to your instruction?
By the way,
Great thanks