Clean up built RPM files.
Make sure we clean out raw_pkgs, if it exists.

We want to make sure the build process does not get confused by
preexisting raw packages in the docker env.
Vastly simplify the Ruby build process.

Since this is a local install of Ruby only, we don't bother splitting
out preinstalled gems, making seperate library patches, or any of that
junk.  We just make one big ruby package.

While we are at it, switch to ruby 2.1.x instead of ruby 2.0.

Flatten

Yay, ruby 2.1.x
Use --no-shell support to make local RPM generation seamless.