Upgrade to go v1.13

Author: chenrui333

.travis.yml

@@ -30,7 +30,7 @@ cache:
     - $HOME/.cache/go-build
 
 go:
-- 1.12.x
+- 1.13.x
 
 # The `x_base_steps` top-level key is unknown to travis,
 # so we can use it to create a bunch of common build step

ci/dockerfiles/builder.Dockerfile

@@ -1,4 +1,4 @@
-FROM openshift/origin-release:golang-1.12
+FROM openshift/origin-release:golang-1.13
 
 WORKDIR /go/src/github.com/operator-framework/operator-sdk
 ENV GOPATH=/go PATH=/go/src/github.com/operator-framework/operator-sdk/build:$PATH GOPROXY=https://proxy.golang.org/ GO111MODULE=on

go.mod

@@ -1,6 +1,6 @@
 module github.com/operator-framework/operator-sdk
 
-go 1.12
+go 1.13
 
 require (
 	cloud.google.com/go v0.37.2 // indirect

release.sh

@@ -23,7 +23,7 @@ if ! $(git diff-index --quiet HEAD --); then
 	exit 1
 fi
 
-GO_VER="1.12"
+GO_VER="1.13"
 if ! go version | cut -d" " -f3 | grep -q "$GO_VER"; then
 	echo "must compile binaries with Go compiler version v${GO_VER}"
 	exit 1