Helpful Listing Aliases

Add alias to list installed rubies. Add alias to list gemsets in active ruby.

plugins/rvm/rvm.plugin.zsh

@@ -2,6 +2,9 @@ fpath=($ZSH/plugins/rvm $fpath)
 autoload -U compinit
 compinit -i
 
+alias rubies='rvm list rubies'
+alias gemsets='rvm gemset list'
+
 local ruby18='ruby-1.8.7-p334'
 local ruby19='ruby-1.9.2-p180'