[API] Updates exists_index_template to return boolean. Addresses #1076

Author: picandocodigo

elasticsearch-api/lib/elasticsearch/api/actions/indices/exists_index_template.rb

@@ -43,10 +43,9 @@ def exists_index_template(arguments = {})
           params = Utils.__validate_and_extract_params arguments, ParamsRegistry.get(__method__)
 
           body = nil
-          if Array(arguments[:ignore]).include?(404)
-            Utils.__rescue_from_not_found { perform_request(method, path, params, body, headers).body }
-          else
-            perform_request(method, path, params, body, headers).body
+
+          Utils.__rescue_from_not_found do
+            perform_request(method, path, params, body, headers).status == 200 ? true : false
           end
         end
 

elasticsearch-api/utils/thor/generator/endpoint_specifics.rb

@@ -27,6 +27,7 @@ module EndpointSpecifics
         exists
         indices.exists
         indices.exists_alias
+        indices.exists_index_template
         indices.exists_template
         indices.exists_type
       ].freeze
@@ -39,7 +40,6 @@ module EndpointSpecifics
         indices.flush_synced
         indices.delete
         indices.delete_index_template
-        indices.exists_index_template
         indices.delete_template
         security.get_role
         security.get_user