Do not install ruby193 because it does not replace the installed ruby...

and it is not required for anything anyway.

Removing some lines because they don't work. In order to make them work, you'd need Yum's `-y` flag but don't do that! Because then you'll:
A) Get the SCL repo
B) Remove Ruby 1.8.7 (/usr/bin/ruby)
C) Install some other stuff including Ruby 1.9.3

Which all sounds peachy except that Ruby 1.9.3 does not replace the removed 1.8.7, so just running `ruby` from the command line will not work unless you first run a subshell. 

Which doesn't sound like too much trouble except that it still doesn't work because any script that starts out with `#!/usr/bin/ruby` will fail to find anything and will not work.

So anyway, why are we doing this? It doesn't accomplish anything and Puppet works just fine with Ruby 1.8.7. So just don't do this.