New unit tests before the functionality I'm about to add.
Add token check endpoint and fix up the tests
Remove explicit request logging as we can turn that on with one line of code, plus clean up comment cruft.
Merge pull request #21 from tidepool-org/kjq/addtokencheck

Fixes #20 and also removes the request logging, because @cheddar pointed out that we can just turn it on with one line of code.