All JS-tests are failing when run with grunt test

If you run the tests for the browser js library by calling "grunt test" as described in the README.md, you'll get 12/12 tests failing with the following Error message:

Testing http://localhost:8088/test.html FFFFFFF
>> global failure
>> Message: ReferenceError: Can't find variable: Thrift
>> http://localhost:8088/test.html:38