Feature/resource catalog

This PR creates removes support for html, xhtml, json home entry point serialization support, and in it's place adds support for `application/vnd.hale+json`.

Example output:
``` json
{
   "_links":{
      "https://www.mydomain.com/philosophers":{
         "href":"https://a-service.io/philosophers",
         "name":"philosophers"
      },
      "https://wormhole-sandbox.imedidata.net/alps/DiscoverableResources#discoverable_resources":{
         "href":"https://wormhole-sandbox.imedidata.net/discoverable_resources",
         "name":"discoverable_resources"
      } 
}
```

Since I have removed features, I would recommend a minor point release change.  This PR does not add a entry to the changelog.