Set up test structure to fit in with edX's Jasmine testrunner

[pdpinch]

In order to add JavaScript tests, we first need to get the test infrastructure set up so that edX can run the tests

[noisecapella]

Getting the tests to run via paver js_test will require editing the paver configuration which hardcodes a list of edx test suites. I talked with @carsongee about his idea for changing the behavior of js-test-tool to search for yml files in installed xblocks, but that's probably far out of the scope of this issue. For now the user will have to run them manually using js-test-tool