rspec 3 breaks passing tests

[zshannon]

To reproduce, install rspec 3.0+ and run rake test. It will produce 3 failures where be_true and be_false are used when rspec 3 expects be_truthy and be_falsey.

We can:

1. lock the gem version to 2+ (as I have in this PR), or,
2. update the tests to support version 3+, which I'm happy to do on this PR if that's the preferred resolution.

[progrium]

Supporting version 3 to keep it fresh would be great!

[zshannon]

@progrium all set.