Fix latest vs. stable in single_user_rvm call

[DracoBlue]

@@ -5,6 +5,7 @@ define rvm::ruby (
   # FIXME: we need to use $user as name here, since single_user_rvm::install_ruby expects it!
   single_user_rvm::install { "${user}":
     user => $user,
+    version => 'latest',
     require => [Exec['rvm-fix-to-install-single-user-rvm-gpg-key']]
   }

Since single_user_rvm goes on stable, but the version check does not contain the string "stable", but "latest"!