move HTTP error responses to GET method
move HTTP error responses to GET method

OpenBEL/openbel-server,nbargnesi/openbel-server,OpenBEL/openbel-api,OpenBEL/openbel-api,OpenBEL/openbel-api,OpenBEL/openbel-server,OpenBEL/openbel-api,nbargnesi/openbel-server,OpenBEL/openbel-server,nbargnesi/openbel-server