Ported code to use rspec 3 from rspec 2

[teyrana]

• mostly straightforward find replaces of test cases
• updates syntax to the rspec 3 matchers

Hello!

I'm not sure how much time you're still putting into this project, but if it's ever come up, here's a version for rspec 3. It doesn't update all of the documentation, but all of the code runs with the new syntax.

-Dan