Move to auth package in faas-provider

The basic-auth middleware and credentials-loading code has been
moved into the faas-provider project. This has now been brought
back into the faas project via vendoring.

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

gateway/vendor/github.com/openfaas/faas-provider/Dockerfile

@@ -0,0 +1,25 @@
+FROM golang:1.9.7-alpine
+
+RUN mkdir -p /go/src/github.com/openfaas/faas-provider/
+
+WORKDIR /go/src/github.com/openfaas/faas-provider
+
+COPY vendor     vendor
+COPY types      types
+COPY auth       auth
+COPY serve.go   .
+
+RUN go test ./auth/ -v \
+    && CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o faas-provider .
+
+FROM alpine:3.7
+RUN apk --no-cache add ca-certificates
+WORKDIR /root/
+
+EXPOSE 8080
+ENV http_proxy      ""
+ENV https_proxy     ""
+
+COPY --from=0 /go/src/github.com/openfaas/faas-provider/faas-provider    .
+
+CMD ["./faas-provider]