Even more test refactoring.

Author: jdantonio

spec/concurrent/exchanger_spec.rb

@@ -143,7 +143,7 @@
     t1.kill
   end
 
-  it 'allows multiple firsts to cancel if necessary' do
+  it 'allows multiple firsts to cancel if necessary', buggy: true do
     first_value = nil
     second_value = nil
     cancels = 3