I have successfully installed rvm, but when I run the following commands
rvm
sudo apt-get update
Or:
rvm install 2
I put @PravinMishra's source into a Gist and now you can simply use this one liner:
wget -O - https://git.io/vvkI4 | bash
NOTE: Don't trust my Gist blindly, download the file and look into it before you run it!