Update of-watchdog to use Go 1.13

Go 1.13 will be used for the distribution version of the watchdog.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Author: alexellis

Dockerfile

@@ -1,6 +1,9 @@
-FROM golang:1.11
+FROM golang:1.13
+
+ARG CGO_ENABLED=0
+ARG GO111MODULE="off"
+ARG GOPROXY=""
 
-RUN mkdir -p /go/src/github.com/openfaas-incubator/of-watchdog
 WORKDIR /go/src/github.com/openfaas-incubator/of-watchdog
 
 COPY vendor              vendor