Update Docker to go1.13.1, alpine3.10, modules, trimpath, latest cons…

…ul and vault

Dockerfile

@@ -1,22 +1,21 @@
-FROM golang:1.11.5-alpine AS build
+FROM golang:1.13.1-alpine AS build
 
-ARG consul_version=1.4.2
+ARG consul_version=1.6.1
 ADD https://releases.hashicorp.com/consul/${consul_version}/consul_${consul_version}_linux_amd64.zip /usr/local/bin
 RUN cd /usr/local/bin && unzip consul_${consul_version}_linux_amd64.zip
 
-ARG vault_version=1.0.3
+ARG vault_version=1.2.3
 ADD https://releases.hashicorp.com/vault/${vault_version}/vault_${vault_version}_linux_amd64.zip /usr/local/bin
 RUN cd /usr/local/bin && unzip vault_${vault_version}_linux_amd64.zip
 
-WORKDIR /go/src/github.com/fabiolb/fabio
+WORKDIR /src
 COPY . .
-ENV GO111MODULE=on
-RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go test -mod=vendor -ldflags "-s -w" ./...
-RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -mod=vendor -ldflags "-s -w"
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go test -mod=vendor -trimpath -ldflags "-s -w" ./...
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -mod=vendor -trimpath -ldflags "-s -w"
 
-FROM alpine:3.8
-RUN apk update && apk add ca-certificates && rm -rf /var/cache/apk/*
-COPY --from=build /go/src/github.com/fabiolb/fabio/fabio /usr/bin
+FROM alpine:3.10
+RUN apk update && apk add --no-cache ca-certificates
+COPY --from=build /src/fabio /usr/bin
 ADD fabio.properties /etc/fabio/fabio.properties
 EXPOSE 9998 9999
 ENTRYPOINT ["/usr/bin/fabio"]