Models: adding update helper method for updating model instance
TemplateResource: adding tested put endpoint
TemplateResource: added tested payload response to delete endpoint
Tests: fixing tests

- different status response code for template post endpoint
- adding put template endpoint url constant
Tests: changing name of template index get test method
TemplateResource: added tested get endpoint
CreateStore: adding default listener for error events
Fetcher: fixing delete method by fixing name of the attribute for super agent
Fetcher: fixing constructing error instance from body meta