CoAP

ENHANCEMENT

1. Describe the enhancement you are requesting.
   Consider using Go errors group (golang.org/x/sync/errgroup) for handling routines in main functions of Mainflux services.

2. Indicate the importance of this enhancement to you (must-have, should-have, nice-to-have).
   This is a nice-to-have.

We are developing a little demo but lobarocoap can't parse a response with no options. it fails of the following code in /src/coap_options.c

if (srcArr[0] == OPTION_PAYLOAD_MARKER) {
		INFO("- Options must not start with payload marker!\r\n");
		return COAP_PARSE_MESSAGE_FORMAT_ERROR;
}

Other clients like libcoap or coapthon or java libraries have no problem with the packets. And

All activities and triggers need to be reviewed, documented and readme updates.