Switching to RSpec for testing

This is the first installment of the potential switch, it illustrates the format of model testing. If anyone has any input on how I can make these tests even better, while maintaining readability, I would really appreciate the help. I purposely only tested one method so that we can focus more on the style versus what is actually being tested. I'm hoping to decide on a style before this PR is merged.  @ferrous26 @zhangsu
I actually think using build_stubbed for the model testing would be okay as well. I don't think its that big of a hassle to open the corresponding factory file and check for the specifications of the mocked object, especially if they are kept organized. What do you think?