VE-1588: Tests for ve.dm.WikiaTemplateModel

Because we make an API request to get all available parameters for a given template, we need to ensure that we don't add all of the empty parameters in the serialize() and getWikiText() methods. This test tests for this scenario.

https://wikia-inc.atlassian.net/browse/VE-1588
"This method used to have an optional second argument called expected. This argument is deprecated and its usage will start throwing errors in 2.0.0. If you're using it, use expect() instead." from http://api.qunitjs.com/QUnit.test/