deps: fix upstream JSON patch issues (#3936)

go.mod,go.sum: bump k8s versions to v1.18.8 and helm to v3.3.4

Signed-off-by: Maartje Eyskens <maartje@eyskens.me>

go.mod

@@ -16,21 +16,21 @@ require (
 	github.com/operator-framework/operator-registry v1.13.4
 	github.com/prometheus/client_golang v1.5.1
 	github.com/sergi/go-diff v1.0.0
-	github.com/sirupsen/logrus v1.5.0
+	github.com/sirupsen/logrus v1.6.0
 	github.com/spf13/afero v1.2.2
 	github.com/spf13/cobra v1.0.0
 	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.4.0
-	github.com/stretchr/testify v1.5.1
+	github.com/stretchr/testify v1.6.1
 	golang.org/x/tools v0.0.0-20200403190813-44a64ad78b9b
 	gomodules.xyz/jsonpatch/v3 v3.0.1
-	helm.sh/helm/v3 v3.2.4
-	k8s.io/api v0.18.6
-	k8s.io/apiextensions-apiserver v0.18.6
-	k8s.io/apimachinery v0.18.6
-	k8s.io/cli-runtime v0.18.2
-	k8s.io/client-go v0.18.6
-	k8s.io/kubectl v0.18.2
+	helm.sh/helm/v3 v3.3.4
+	k8s.io/api v0.18.8
+	k8s.io/apiextensions-apiserver v0.18.8
+	k8s.io/apimachinery v0.18.8
+	k8s.io/cli-runtime v0.18.8
+	k8s.io/client-go v0.18.8
+	k8s.io/kubectl v0.18.8
 	rsc.io/letsencrypt v0.0.3 // indirect
 	sigs.k8s.io/controller-runtime v0.6.2
 	sigs.k8s.io/controller-tools v0.3.0