Bump sigs.k8s.io/controller-tools from 0.8.0 to 0.13.0

Bumps [sigs.k8s.io/controller-tools](https://github.com/kubernetes-sigs/controller-tools) from 0.8.0 to 0.13.0.
- [Release notes](https://github.com/kubernetes-sigs/controller-tools/releases)
- [Changelog](https://github.com/kubernetes-sigs/controller-tools/blob/master/RELEASE.md)
- [Commits](kubernetes-sigs/controller-tools@v0.8.0...v0.13.0)

---
updated-dependencies:
- dependency-name: sigs.k8s.io/controller-tools
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

go.mod

@@ -3,24 +3,9 @@ module github.com/szuecs/routegroup-client
 go 1.15
 
 require (
-	github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6 // indirect
-	github.com/coreos/go-etcd v2.0.0+incompatible // indirect
-	github.com/cpuguy83/go-md2man v1.0.10 // indirect
 	github.com/davecgh/go-spew v1.1.1
-	github.com/docker/docker v0.7.3-0.20190327010347-be7ac8be2ae0 // indirect
-	github.com/docker/spdystream v0.0.0-20160310174837-449fdfce4d96 // indirect
-	github.com/go-openapi/spec v0.19.5 // indirect
-	github.com/go-openapi/validate v0.19.5 // indirect
-	github.com/gophercloud/gophercloud v0.1.0 // indirect
-	github.com/ugorji/go v1.1.4 // indirect
-	github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8 // indirect
-	github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77 // indirect
-	go.etcd.io/etcd v0.0.0-20191023171146-3cf2f69b5738 // indirect
-	gotest.tools v2.2.0+incompatible // indirect
-	k8s.io/apimachinery v0.23.17
-	k8s.io/client-go v0.23.17
-	k8s.io/code-generator v0.23.17
-	k8s.io/klog v1.0.0 // indirect
-	sigs.k8s.io/controller-tools v0.8.0
-	sigs.k8s.io/structured-merge-diff/v3 v3.0.0 // indirect
+	k8s.io/apimachinery v0.28.0
+	k8s.io/client-go v0.28.0
+	k8s.io/code-generator v0.28.0
+	sigs.k8s.io/controller-tools v0.13.0
 )