Update v0.18.3 -> v0.20.2

Including...
• Regenerate go.mod using hack/update-k8s-version.sh
• kubectl has its own repo now, k8s.io/kubectl
• bump go version in go.mod to 1.15

go.mod

@@ -1,48 +1,42 @@
 module github.com/evanlucas/kcfishgen
 
-go 1.14
+go 1.15
 
 require (
-	github.com/Microsoft/hcsshim v0.8.6 // indirect
-	github.com/checkpoint-restore/go-criu v0.0.0-20190109184317-bdb7599cd87b // indirect
-	github.com/cloudflare/cfssl v0.0.0-20180726162950-56268a613adf // indirect
-	github.com/coreos/etcd v3.3.15+incompatible // indirect
-	github.com/coreos/rkt v1.30.0 // indirect
-	github.com/docker/libnetwork v0.0.0-20180830151422-a9cd636e3789 // indirect
-	github.com/godbus/dbus v4.1.0+incompatible // indirect
-	github.com/google/certificate-transparency-go v1.0.21 // indirect
-	github.com/heketi/rest v0.0.0-20180404230133-aa6a65207413 // indirect
-	github.com/heketi/utils v0.0.0-20170317161834-435bc5bdfa64 // indirect
-	github.com/opencontainers/runc v1.0.0-rc2.0.20190611121236-6cc515888830 // indirect
-	github.com/spf13/cobra v0.0.5
+	github.com/spf13/cobra v1.1.1
 	github.com/spf13/pflag v1.0.5
-	k8s.io/kubernetes v1.18.3
-	sigs.k8s.io/structured-merge-diff v0.0.0-20190525122527-15d366b2352e // indirect
+	k8s.io/kubectl v0.20.2
 )
 
 replace (
-	k8s.io/api => k8s.io/api v0.18.3
-	k8s.io/apiextensions-apiserver => k8s.io/apiextensions-apiserver v0.18.3
-	k8s.io/apimachinery => k8s.io/apimachinery v0.18.4-rc.0
-	k8s.io/apiserver => k8s.io/apiserver v0.18.3
-	k8s.io/cli-runtime => k8s.io/cli-runtime v0.18.3
-	k8s.io/client-go => k8s.io/client-go v0.18.3
-	k8s.io/cloud-provider => k8s.io/cloud-provider v0.18.3
-	k8s.io/cluster-bootstrap => k8s.io/cluster-bootstrap v0.18.3
-	k8s.io/code-generator => k8s.io/code-generator v0.18.4-rc.0
-	k8s.io/component-base => k8s.io/component-base v0.18.3
-	k8s.io/cri-api => k8s.io/cri-api v0.18.4-rc.0
-	k8s.io/csi-translation-lib => k8s.io/csi-translation-lib v0.18.3
-	k8s.io/kube-aggregator => k8s.io/kube-aggregator v0.18.3
-	k8s.io/kube-controller-manager => k8s.io/kube-controller-manager v0.18.3
-	k8s.io/kube-proxy => k8s.io/kube-proxy v0.18.3
-	k8s.io/kube-scheduler => k8s.io/kube-scheduler v0.18.3
-	k8s.io/kubectl => k8s.io/kubectl v0.18.3
-	k8s.io/kubelet => k8s.io/kubelet v0.18.3
-	k8s.io/legacy-cloud-providers => k8s.io/legacy-cloud-providers v0.18.3
-	k8s.io/metrics => k8s.io/metrics v0.18.3
+	k8s.io/api => k8s.io/api v0.20.2
+	k8s.io/apiextensions-apiserver => k8s.io/apiextensions-apiserver v0.20.2
+	k8s.io/apimachinery => k8s.io/apimachinery v0.21.0-alpha.0
+	k8s.io/apiserver => k8s.io/apiserver v0.20.2
+	k8s.io/cli-runtime => k8s.io/cli-runtime v0.20.2
+	k8s.io/client-go => k8s.io/client-go v0.20.2
+	k8s.io/cloud-provider => k8s.io/cloud-provider v0.20.2
+	k8s.io/cluster-bootstrap => k8s.io/cluster-bootstrap v0.20.2
+	k8s.io/code-generator => k8s.io/code-generator v0.20.3-rc.0
+	k8s.io/component-base => k8s.io/component-base v0.20.2
+	k8s.io/cri-api => k8s.io/cri-api v0.20.3-rc.0
+	k8s.io/csi-translation-lib => k8s.io/csi-translation-lib v0.20.2
+	k8s.io/kube-aggregator => k8s.io/kube-aggregator v0.20.2
+	k8s.io/kube-controller-manager => k8s.io/kube-controller-manager v0.20.2
+	k8s.io/kube-proxy => k8s.io/kube-proxy v0.20.2
+	k8s.io/kube-scheduler => k8s.io/kube-scheduler v0.20.2
+	k8s.io/kubectl => k8s.io/kubectl v0.20.2
+	k8s.io/kubelet => k8s.io/kubelet v0.20.2
+	k8s.io/legacy-cloud-providers => k8s.io/legacy-cloud-providers v0.20.2
+	k8s.io/metrics => k8s.io/metrics v0.20.2
 	k8s.io/node-api => k8s.io/node-api v0.0.0-20191003003902-772c6d2244f3
-	k8s.io/sample-apiserver => k8s.io/sample-apiserver v0.18.3
-	k8s.io/sample-cli-plugin => k8s.io/sample-cli-plugin v0.18.3
-	k8s.io/sample-controller => k8s.io/sample-controller v0.18.3
+	k8s.io/sample-apiserver => k8s.io/sample-apiserver v0.20.2
+	k8s.io/sample-cli-plugin => k8s.io/sample-cli-plugin v0.20.2
+	k8s.io/sample-controller => k8s.io/sample-controller v0.20.2
 )
+
+replace k8s.io/component-helpers => k8s.io/component-helpers v0.20.2
+
+replace k8s.io/controller-manager => k8s.io/controller-manager v0.20.2
+
+replace k8s.io/mount-utils => k8s.io/mount-utils v0.20.3-rc.0