Revert to 0.18.8 of K8s (ko-build#279)

Author: mattmoor

go.mod

@@ -8,7 +8,6 @@ require (
 	github.com/docker/docker v1.4.2-0.20190924003213-a8608b5b67c7
 	github.com/dprotaso/go-yit v0.0.0-20191028211022-135eb7262960
 	github.com/fsnotify/fsnotify v1.4.9
-	github.com/go-logr/logr v0.3.0 // indirect
 	github.com/go-training/helloworld v0.0.0-20200225145412-ba5f4379d78b
 	github.com/google/go-cmp v0.5.2
 	github.com/google/go-containerregistry v0.3.0
@@ -29,14 +28,13 @@ require (
 	gotest.tools/v3 v3.0.2 // indirect
 	k8s.io/apimachinery v0.19.6
 	k8s.io/cli-runtime v0.18.8
-	k8s.io/klog/v2 v2.4.0 // indirect
-	k8s.io/kube-openapi v0.0.0-20201113171705-d219536bb9fd // indirect
+	k8s.io/kube-openapi v0.0.0-20200410145947-bcb3869e6f29 // indirect
 	sigs.k8s.io/kind v0.8.1
 )
 
 replace (
-	k8s.io/api => k8s.io/api v0.19.6
-	k8s.io/apimachinery => k8s.io/apimachinery v0.19.6
-	k8s.io/cli-runtime => k8s.io/cli-runtime v0.19.6
-	k8s.io/client-go => k8s.io/client-go v0.19.6
+	k8s.io/api => k8s.io/api v0.18.8
+	k8s.io/apimachinery => k8s.io/apimachinery v0.18.8
+	k8s.io/cli-runtime => k8s.io/cli-runtime v0.18.8
+	k8s.io/client-go => k8s.io/client-go v0.18.8
 )