Fix CTRL-Y key binding

With tmux-based test cases

Rakefile

@@ -2,8 +2,11 @@ require "bundler/gem_tasks"
 require 'rake/testtask'
 
 Rake::TestTask.new(:test) do |test|
-  test.pattern = 'test/**/test_*.rb'
-  test.verbose = true
+  test.pattern = 'test/test_go.rb'
+end
+
+Rake::TestTask.new(:testall) do |test|
+  test.pattern = 'test/test_*.rb'
 end
 
 task :default => :test