rspec/rspec-expectations — pull request #218 by mrkn (2013-03-12 06:12:42+00:00)
Title: Fix have matcher for Enumerator on Ruby 2.0.0

Since Ruby 2.0.0, an Enumerator responds to ```size```, and it returns ```nil``` if the size is unknown.
So ```have``` matcher for an Enumerator is broken on Ruby 2.0.0.