chore: update go toolchain to 1.12.7 (#1658)

See https://github.com/deis/docker-go-dev/releases/tag/v1.22.4
and https://github.com/golang/go/issues?q=milestone%3AGo1.12.6

.devcontainer.json

@@ -1,6 +1,6 @@
 {
 	"name": "Go for aks-engine",
-	"image": "quay.io/deis/go-dev:v1.22.3",
+	"image": "quay.io/deis/go-dev:v1.22.4",
 	"extensions": [
 		"ms-vscode.go"
 	],

.pipelines/pr-e2e.yaml

@@ -17,7 +17,7 @@ pr:
 resources:
   containers:
   - container: dev1
-    image: quay.io/deis/go-dev:v1.22.3
+    image: quay.io/deis/go-dev:v1.22.4
 
 jobs:
 - job: unit_tests

Makefile

@@ -25,7 +25,7 @@ GITTAG := $(VERSION_SHORT)
 endif
 
 REPO_PATH := github.com/Azure/$(PROJECT)
-DEV_ENV_IMAGE := quay.io/deis/go-dev:v1.22.3
+DEV_ENV_IMAGE := quay.io/deis/go-dev:v1.22.4
 DEV_ENV_WORK_DIR := /go/src/$(REPO_PATH)
 DEV_ENV_OPTS := --rm -v $(CURDIR):$(DEV_ENV_WORK_DIR) -w $(DEV_ENV_WORK_DIR) $(DEV_ENV_VARS)
 DEV_ENV_CMD := docker run $(DEV_ENV_OPTS) $(DEV_ENV_IMAGE)

makedev.ps1

@@ -1,5 +1,5 @@
 $REPO_PATH = "github.com/Azure/aks-engine"
-$DEV_ENV_IMAGE = "quay.io/deis/go-dev:v1.22.3"
+$DEV_ENV_IMAGE = "quay.io/deis/go-dev:v1.22.4"
 $DEV_ENV_WORK_DIR = "/go/src/$REPO_PATH"
 
 docker.exe run -it --rm -w $DEV_ENV_WORK_DIR -v `"$($PWD)`":$DEV_ENV_WORK_DIR $DEV_ENV_IMAGE bash