Please provide checksums (sha512) for each ruby download

[douglasdd]

If there were sha512 checksums for the files provided at URLs like the one below, users would have more confidence in the process, and the RVM tool would stop complaining
"No checksum for downloaded archive, recording checksum in user configuration."
Even diligent users who then go find the file ~/rvm/usre/sha512 have nothing to compare it with at the source site:
http://rubies.travis-ci.org/ubuntu/12.04/x86_64/ruby-2.2.4

PS - Thanks for all this! I first heard of RVM an hour ago, and now I'm running a current version and the gem that I was looking for on my Ubuntu 12.04 system (only has Ruby 1.8 or 1.9.1)