Introduce Busted.start and Busted.finish
Allow user to "sandwich" code and report invalidations

* Add start and finish tests
* Refactor Profiler duck type to require .run class method
* Add Busted.start and Busted.finish class methods
* Add Sandwich Profiler to power start and finish api
* Autoload profilers
* Update README
git merge master
Since Sandwich is a Singleton, reset report on each run
Merge pull request #10 from simeonwillbanks/start-finish-api

Introduce Busted.start and Busted.finish