chore: improve Dockerfile.

Author: ldez

Dockerfile

@@ -4,17 +4,23 @@ RUN apk --update upgrade \
 && apk --no-cache --no-progress add git make \
 && rm -rf /var/cache/apk/*
 
-WORKDIR /go/src/github.com/containous/kutteri
-COPY . .
+WORKDIR /go/kutteri
+
+ENV GO111MODULE on
 
+# Download go modules
+COPY go.mod .
+COPY go.sum .
 RUN go mod download
+
+COPY . .
 RUN make build
 
 FROM alpine:3.6
 RUN apk --update upgrade \
     && apk --no-cache --no-progress add ca-certificates git \
     && rm -rf /var/cache/apk/*
 
-COPY --from=builder /go/src/github.com/containous/kutteri/kutteri /usr/bin/kutteri
+COPY --from=builder /go/kutteri/kutteri /usr/bin/kutteri
 
 ENTRYPOINT ["/usr/bin/kutteri"]