decode SUPPORTED frames correctly, that are send in response to options messages and periodical pings

conn.go

@@ -454,6 +454,8 @@ func (c *Conn) decodeFrame(f frame, trace Tracer) (rval interface{}, err error)
 		default:
 			return nil, ErrProtocol
 		}
+	case opSupported:
+		return supportedFrame{}, nil
 	case opError:
 		code := f.readInt()
 		msg := f.readString()

frame.go

@@ -286,6 +286,8 @@ var consistencyCodes = []uint16{
 
 type readyFrame struct{}
 
+type supportedFrame struct{}
+
 type resultVoidFrame struct{}
 
 type resultRowsFrame struct {