install ruby 1.9.2 and Rails 3.1 RC

gistfile1.bash

This example shows how to setup an environment running Rails 3 under 1.9.2 with a 'rails3' gem set.

∴ rvm update --head
# ((Open a new shell)) or do 'rvm reload'

# If you do not already have the ruby interpreter installed, install it:
∴ rvm install 1.9.2

# Switch to 1.9.2-head and gemset rails31rc, create if it doesn't exist. 
∴ rvm --create use 1.9.2@rails31rc

# Install Rails 3.1 release candidate
∴ gem install rails --pre

# Check to see we now have Rails 3
∴ rails --version
Rails 3.1.0.rc4