JSCBC-104 update the test configuration

* adding mocha globals
* ignoring the local test config.json configuration file.

Change-Id: I9a71fadfd1df42e2376aa4c97437dd824a6aeb34
Reviewed-on: http://review.couchbase.org/36131
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Brett Lawson <brett19@gmail.com>