Actually pass phantomjs-options on to PhantomJS

Before this change, options specified using...

qunit({'phantomjs-options': ['--ssl-protocol=any']})

... were silently dropped by gulp-qunit.

The test case for this change passes --help to PhantomJS and verifies
that:
a) No tests are run
b) Some help is received

Without the changes to index.js, this test case fails.