Properly test mosaic routes

[jisantuc]

Improvement

As is, the mosaic route tests are part of the collections spec. To turn the routes on, you have to create the collections service with enableTiles set to true. However, when you do so, some equality expectations for the collections service spec are violated (probably via the inclusion of links though I didn't look too closely). To properly test the mosaic json routes, we should separate the tests (and actually test the list endpoint).