setup.rb in sinatra-contrib-2.0.3

- old
+ new

@@ -1,7 +1,7 @@
 require 'sinatra/base'
 require 'sinatra/contrib/version'
-require 'backports'
+require 'backports/rails/string' # for String#underscore
 
 module Sinatra
   module Contrib
     module Loader
       def extensions