function createTempDirectory() {
        var deferred = new $.Deferred();

        runs(function () {
            _getFileSystem().getDirectoryForPath(getTempDirectory()).create(function (err) {
                if (err && err !== FileSystemError.ALREADY_EXISTS) {
                    deferred.reject(err);
                } else {
                    deferred.resolve();
                }
            });
        });

        waitsForDone(deferred, "Create temp directory", 500);
    }
Create the temporary unit test project directory.