😒 Remove parameter fixes watson-developer-cloud#86

Remove a parameter from the `delete_collection` method in the retrieve and rank service

Author: germanattanasio

watson_developer_cloud/retrieve_and_rank_v1.py

@@ -68,7 +68,7 @@ def create_collection(self, solr_cluster_id, collection_name, config_name):
         return self.request(method='POST', url='/v1/solr_clusters/{0}/solr/admin/collections'.format(solr_cluster_id),
                             params=params, accept_json=True)
 
-    def delete_collection(self, solr_cluster_id, collection_name, config_name):
+    def delete_collection(self, solr_cluster_id, collection_name):
         params = {'name': collection_name, 'action': 'DELETE', 'wt': 'json'}
         return self.request(method='POST', url='/v1/solr_clusters/{0}/solr/admin/collections'.format(solr_cluster_id),
                             params=params, accept_json=True)