Re-vendor queue-worker publisher for reconnect

- re-vendor queue-worker for publisher via 0.6.0
- bump queue-worker version to 0.6.0 in docker-compose.yml for
AMD64
- use new naming for NATS of nats -> NATS in variables where
required
- add default reconnect of 60 times, 2 seconds apart.

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

gateway/vendor/github.com/openfaas/nats-queue-worker/Dockerfile

@@ -1,14 +1,18 @@
-FROM golang:1.9.7-alpine as golang
+FROM golang:1.10-alpine as golang
 WORKDIR /go/src/github.com/openfaas/nats-queue-worker
 
 COPY vendor     vendor
 COPY handler    handler
+COPY nats       nats
 COPY main.go  .
+COPY readconfig.go .
+COPY readconfig_test.go .
+COPY auth.go .
 
-RUN go test -v ./handler/
+RUN go test -v ./...
 RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .
 
-FROM alpine:3.7
+FROM alpine:3.8
 
 RUN addgroup -S app \
   && adduser -S -g app app \