Add sinon.js to testing suite for better spying, mocking and stubbing

Fixes #847
Test code clean up
Leverage spies and stubs in tests
Fix Typo benifit -> benefits
Fix my own Typo in View Documentation
Merge pull request #870 from stsc3000/patch-1

Fix Typo in View Documentation: benifit -> benefits
Merge pull request #856 from cobbweb/feature/add-sinonjs-to-test-suite

Add Sinon.js for better spying, stubbing and mocking
Make CollectionView#checkEmpty overridable
Add isEmpty for overriding empty view rendering
Add isEmpty reference to docs
Clean up tests
Remove extra jQuery calls and fix spelling error
Merge pull request #832 from parklet/new-override-check-empty

Change CollectionView#checkEmpty to be overridable
Allow modules to be extended

Custom modules can now be created using the extend method, and then attached to an Application. Documentation and tests were added for this new functionality.
Merge pull request #845 from jmeas/master

Extended `module` functionality
Remove unnecessary blank lines