Minor cleanup
Remove SwitchCase from coverage. Closes #61
modified structure of experiments

* added more information about experiments inline with tests
* experiments and tests now have a reference to their parent
modified execution of experiments

* execute tests and experiments as a tree rather than list
* emit start, startExperiment, and endExperiment events
* queried potential issue with deep nested tests and beforeEach/afterEach
made color an internal function and refactored formatErrors into formatSummary
extract console summary into an internal function
added spec formatter