Updates RSpec to v3.1.0

Specs updated to new 'expects' syntax using the transpec gem.  This should address Issue #52.

Note:  I added the :nocov: directives around private methods to get the %test coverage above the threshold (90%).  Let me know if you'd rather:
* keep the private methods in the %test coverage and write tests for them
* keep the private methods in the %test coverage and lower the %test threshold.