Added note to readme about spider

Added a small note to please to remember to extend the spider as new
functionality is added to the API. The spider is essentially our unit
test and I'm inclined to setup my git hooks for this repository to run
it before pushing.
Spider assertion updates and Raw test

References #88

Added assertions to enforce that the validation methods are returning
true instead of just relying on the assertion tests passing.

Added verification on the new raw field to ensure that it is working
properly.