Update to golang 1.9.7

Issue #660 has been open for a while to update to 1.9.6, this
performs the update to the latest in the 1.9 release (1.9.7)

Signed-off-by: Sean Smith <sean@wwsean08.com>

DEV.md

@@ -26,7 +26,7 @@ You can find the [reference documentation for the Watchdog here](https://github.
 This is the basis of a function which generates HTML from MarkDown:
 
 ```
-FROM golang:1.9.4
+FROM golang:1.9.7
 RUN mkdir -p /go/src/app
 COPY handler.go /go/src/app
 WORKDIR /go/src/app

gateway/Dockerfile

-FROM golang:1.9.4 as build
+FROM golang:1.9.7 as build
 
 RUN curl -sL https://github.com/alexellis/license-check/releases/download/0.2.2/license-check \
       > /usr/bin/license-check \

gateway/Dockerfile.arm64

-#FROM alexellis2/golang:1.9-arm64 as build
-FROM golang:1.9.2 as build
+FROM golang:1.9.7 as build
 WORKDIR /go/src/github.com/openfaas/faas/gateway
 
 #RUN curl -sL https://github.com/alexellis/license-check/releases/download/0.1/license-check > /usr/bin/license-check && chmod +x /usr/bin/license-check

gateway/Dockerfile.armhf

-FROM golang:1.9.6 as build
+FROM golang:1.9.7 as build
 
 WORKDIR /go/src/github.com/openfaas/faas/gateway
 

sample-functions/ApiKeyProtected-Secrets/Dockerfile

-FROM golang:1.9.4-alpine as builder
+FROM golang:1.9.7-alpine as builder
 
 MAINTAINER alex@openfaas.com
 ENTRYPOINT []

sample-functions/BaseFunctions/golang/Dockerfile

-FROM golang:1.9.4-alpine
+FROM golang:1.9.7-alpine
 
 MAINTAINER alexellis2@gmail.com
 ENTRYPOINT []

sample-functions/BaseFunctions/golang/Dockerfile.win

-FROM golang:1.9.4-windowsservercore
+FROM golang:1.9.7-windowsservercore
 MAINTAINER alexellis2@gmail.com
 ENTRYPOINT []
 

sample-functions/DockerHubStats/Dockerfile

-FROM golang:1.9.4-alpine as builder
+FROM golang:1.9.7-alpine as builder
 
 MAINTAINER alex@openfaas.com
 ENTRYPOINT []

sample-functions/DockerHubStats/Dockerfile.armhf

-FROM golang:1.9.4-alpine as builder
+FROM golang:1.9.7-alpine as builder
 
 MAINTAINER alex@openfaas.com
 ENTRYPOINT []

sample-functions/MarkdownRender/Dockerfile

-FROM golang:1.9.4-alpine as builder
+FROM golang:1.9.7-alpine as builder
 
 MAINTAINER alex@openfaas.com
 ENTRYPOINT []

sample-functions/WebhookStash/Dockerfile

-FROM golang:1.9.4-alpine as builder
+FROM golang:1.9.7-alpine as builder
 
 MAINTAINER alex@openfaas.com
 ENTRYPOINT []

watchdog/Dockerfile

-FROM golang:1.9.4 as build
+FROM golang:1.9.7 as build
 ARG VERSION
 ARG GIT_COMMIT