Merge pull request #4991 from rolandwalker/silence_stderr_interface

Remove comment recommending :silence_stderr

lib/cask/system_command.rb

@@ -34,7 +34,6 @@ class Cask::SystemCommand
 
   def self._process_options(executable, options)
     options.assert_valid_keys :input, :print, :stderr, :args, :must_succeed, :sudo, :plist
-    # would probably be better to change :stderr to boolean :silence_stderr
     if options[:stderr] and options[:stderr] != :silence
       raise CaskError.new "Unknown value #{options[:stderr]} for key :stderr"
     end