resolve test-suite incompatibilities with rspec3

This build failed:
https://travis-ci.org/natritmeyer/site_prism/jobs/28803569

Cause:
https://github.com/rspec/rspec-expectations/commit/d71bff4e81059494d9fdc09ccf5694164dbc038e#comments
and
https://github.com/rspec/rspec-expectations/issues/283

Rather then pulling in rspec-collection_matchers I've just adjusted the steps to work without it.  We may want to configure travis to test with rspec2 and rspec3 going forward.