Add mocha using npm
Add Makefile to run mocha tests easily
Set up a basic test
Separate declaration from invocation for testability
Write a testable public interface

This hooks up to the old handleText function for now.
Switch everything over to the new object-oriented approach with tests
Add Travis config file to get CI working
Add Travis build badge to README
Add tests for witnesses and new study
Merge branch 'master' of github.com:h2s/xkcd-substitutions into patch-1

Conflicts:
	Source/content_script.js