Merge pull request #527 from ruby-syntax-tree/move-yarv

Move YARV out of syntax tree

Author: kddnewton

exe/yarv

@@ -35,7 +35,6 @@ module SyntaxTree
   autoload :PrettyPrintVisitor, "syntax_tree/pretty_print_visitor"
   autoload :Search, "syntax_tree/search"
   autoload :WithScope, "syntax_tree/with_scope"
-  autoload :YARV, "syntax_tree/yarv"
 
   # This holds references to objects that respond to both #parse and #format
   # so that we can use them in the CLI.