Refactor use protbof to send messages and remove unused "distance" metrics

go.mod

@@ -4,6 +4,10 @@ go 1.13
 
 require (
 	github.com/cyrilix/robocar-base v0.0.0-20191229155957-683a9d53e6b8
+	github.com/cyrilix/robocar-protobuf/go v0.0.0-20200101000356-accf7184079a
+	github.com/eclipse/paho.mqtt.golang v1.2.0
+	github.com/golang/protobuf v1.3.2
+	github.com/sirupsen/logrus v1.2.0
 	github.com/tarm/serial v0.0.0-20180830185346-98f6abe2eb07
 	golang.org/x/net v0.0.0-20191209160850-c0dbc17a3553 // indirect
 	golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9 // indirect