Update MarkdownRender sample-function to use new approach

    I used AlpineFunction as the example to follow as suggested by
    @alexellis

Signed-off-by: scott.eppler <scott.eppler@coda.global>

sample-functions/MarkdownRender/Dockerfile

+FROM openfaas/classic-watchdog:0.14.4 as watchdog
+
 FROM golang:1.11-alpine as builder
 ENV CGO_ENABLED=0
 
@@ -11,10 +13,10 @@ COPY vendor vendor
 
 RUN go install
 
-FROM functions/alpine:latest
+FROM alpine:3.10
 
-# Needed to reach the hub
-RUN apk --no-cache add ca-certificates 
+COPY --from=watchdog /fwatchdog /usr/bin/fwatchdog
+RUN chmod +x /usr/bin/fwatchdog
 
 COPY --from=builder /go/bin/MarkdownRender  /usr/bin/MarkdownRender
 ENV fprocess "/usr/bin/MarkdownRender"