Adding Type on collections page for tiles and coverages (#834)

* - Adding the 'type' of the collection in the collections endpoint, for 'coverages' and 'tiles'

* - removed support for adding "coverage" keyword, due to failing test

Co-authored-by: doublebyte1 <info@doublebyte.net>

pygeoapi/api.py

@@ -882,7 +882,7 @@ class API:
                     self.config['server']['url'], k, F_HTML)
             })
 
-            if collection_data_type in ['feature', 'record']:
+            if collection_data_type in ['feature', 'record', 'tile']:
                 # TODO: translate
                 collection['itemType'] = collection_data_type
                 LOGGER.debug('Adding feature/record based links')