require "irb/output-method" for StdioOutputMethod

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57071 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/irb/context.rb

@@ -11,6 +11,7 @@
 #
 require "irb/workspace"
 require "irb/inspector"
+require "irb/output-method"
 
 module IRB
   # A class that wraps the current state of the irb session, including the