Bump Golang 1.12.2

go1.12.2 (released 2019/04/05) includes fixes to the compiler, the go
command, the runtime, and the doc, net, net/http/httputil, and os packages.
See the Go 1.12.2 milestone on our issue tracker for details:

https://github.com/golang/go/issues?q=milestone%3AGo1.12.2

Full diff: https://github.com/golang/go/compare/go1.12.1...go1.12.2

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Dockerfile

@@ -24,7 +24,7 @@
 # the case. Therefore, you don't have to disable it anymore.
 #
 
-FROM golang:1.12.1 AS base
+FROM golang:1.12.2 AS base
 # allow replacing httpredir or deb mirror
 ARG APT_MIRROR=deb.debian.org
 RUN sed -ri "s/(httpredir|deb).debian.org/$APT_MIRROR/g" /etc/apt/sources.list

Dockerfile.e2e

@@ -1,5 +1,5 @@
 ## Step 1: Build tests
-FROM golang:1.12.1-alpine3.9 as builder
+FROM golang:1.12.2-alpine as builder
 
 RUN apk --no-cache add \
     bash \

Dockerfile.simple

@@ -5,7 +5,7 @@
 
 # This represents the bare minimum required to build and test Docker.
 
-FROM golang:1.12.1
+FROM golang:1.12.2
 
 # allow replacing httpredir or deb mirror
 ARG APT_MIRROR=deb.debian.org

Dockerfile.windows

@@ -168,7 +168,7 @@ SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPref
 # Environment variable notes:
 #  - GO_VERSION must be consistent with 'Dockerfile' used by Linux.
 #  - FROM_DOCKERFILE is used for detection of building within a container.
-ENV GO_VERSION=1.12.1 `
+ENV GO_VERSION=1.12.2 `
     GIT_VERSION=2.11.1 `
     GOPATH=C:\go `
     FROM_DOCKERFILE=1