Performs a GET request on the endpoint as specified by
resource_url.
request( resource_url, base_url = ensembl_server(), verbose = FALSE, warnings = TRUE )
| resource_url | Endpoint URL. The endpoint is internally appended to the
  | 
    
|---|---|
| base_url | The Ensembl REST API base URL.  | 
    
| verbose | Whether to be verbose.  | 
    
| warnings | Whether to print warnings.  | 
    
A named list of four elements:
The URL endpoint.
A string describing the status of the response obtained:
"OK" if successful or a description the error.
The parsed JSON as a nested list, as returned by
fromJSON.