Build: Minimum Go version is now 1.10 (#409)

f110 · Tom Limoncelli · commit 8b5cd19de568 · 2018-10-02T10:29:32.000-04:00
Can not build by go version under 1.9.
because using the strings.Builder by library.
diff --git a/Dockerfile b/Dockerfile
@@ -1,4 +1,4 @@
-FROM golang:1.9-alpine AS build-env
+FROM golang:1.10-alpine AS build-env
 WORKDIR /go/src/github.com/StackExchange/dnscontrol
 ADD . .
 RUN apk update && apk add git
diff --git a/README.md b/README.md
@@ -96,7 +96,7 @@ Writing new plugins is very easy.
 
 ## From source
 
-DNSControl can be built with Go version 1.7 or higher. To install, simply run 
+DNSControl can be built with Go version 1.10 or higher. To install, simply run
 
 `go get github.com/StackExchange/dnscontrol`
 

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-FROM golang:1.9-alpine AS build-env`
	`1`	`+FROM golang:1.10-alpine AS build-env`
`2`	`2`	`WORKDIR /go/src/github.com/StackExchange/dnscontrol`
`3`	`3`	`ADD . .`
`4`	`4`	`RUN apk update && apk add git`