functional: use Go 1.12.7 as default

Signed-off-by: Gyuho Lee <leegyuho@amazon.com>

Makefile

@@ -65,11 +65,11 @@ endif
 
 
 # Example:
-#   GO_VERSION=1.10.7 make build-docker-test
+#   GO_VERSION=1.12.7 make build-docker-test
 #   make build-docker-test
 #
 #   gcloud docker -- login -u _json_key -p "$(cat /etc/gcp-key-etcd-development.json)" https://gcr.io
-#   GO_VERSION=1.10.7 make push-docker-test
+#   GO_VERSION=1.12.7 make push-docker-test
 #   make push-docker-test
 #
 #   gsutil -m acl ch -u allUsers:R -r gs://artifacts.etcd-development.appspot.com

functional/scripts/docker-local-agent.sh

@@ -13,7 +13,7 @@ if ! [[ "${0}" =~ "scripts/docker-local-agent.sh" ]]; then
 fi
 
 if [[ -z "${GO_VERSION}" ]]; then
-  GO_VERSION=1.10.1
+  GO_VERSION=1.12.7
 fi
 echo "Running with GO_VERSION:" ${GO_VERSION}
 

functional/scripts/docker-local-tester.sh

@@ -6,7 +6,7 @@ if ! [[ "${0}" =~ "scripts/docker-local-tester.sh" ]]; then
 fi
 
 if [[ -z "${GO_VERSION}" ]]; then
-  GO_VERSION=1.10.1
+  GO_VERSION=1.12.7
 fi
 echo "Running with GO_VERSION:" ${GO_VERSION}