add teaspoon javascript test suite

Added teaspoon javascript testing with mocha, sinon, chai and phantomjs.  Also added a test for chai assertions to make sure they are working as expected.  You can run the test suite the following ways..

#1 in the browser at: '/javascript_test'
#2 via console: 'rake spec:javascript'
#3 and using just 'rake'... runs with the other test