change from K8s to k8s (IBM#260)

* change from K8s to k8s

* fix tested cluster version

Author: yuji-watanabe-jp

docs/README_OPERATOR_HUB.md

@@ -1,7 +1,7 @@
-# K8s Integrity Shield
-K8s Integrity Shield is a tool for built-in preventive integrity control for regulated cloud workloads. It includes signature based configuration drift prevention based on Admission Webhook on Kubernetes cluster.
+# k8s Integrity Shield
+k8s Integrity Shield is a tool for built-in preventive integrity control for regulated cloud workloads. It includes signature based configuration drift prevention based on Admission Webhook on Kubernetes cluster.
 
-K8s Integrity Shield's capabilities are
+k8s Integrity Shield's capabilities are
 
 - Allow to deploy authorized application pakcages only
 - Allow to use signed deployment params only
@@ -129,10 +129,10 @@ configmap/test-cm created
 
 ## Supported Platforms
 
-K8s Integrity Shield works as Kubernetes Admission Controller using Mutating Admission Webhook, and it can run on any Kubernetes cluster by design. 
+k8s Integrity Shield works as Kubernetes Admission Controller using Mutating Admission Webhook, and it can run on any Kubernetes cluster by design.
 We have verified the feasibility on the following platforms:
 
 - [RedHat OpenShift 4.5 and 4.6](https://www.openshift.com/)
-- [RedHat OpenShift 4.3 on IBM Cloud (ROKS)](https://www.openshift.com/products/openshift-ibm-cloud)
+- [RedHat OpenShift 4.5 on IBM Cloud (ROKS)](https://www.openshift.com/products/openshift-ibm-cloud)
 - [IBM Kuberenetes Service (IKS)](https://www.ibm.com/cloud/container-service/) 1.17.14
 - [Minikube v1.19.1](https://kubernetes.io/docs/setup/learning-environment/minikube/)

shield/pkg/util/kubeutil/dryrun.go

@@ -47,7 +47,7 @@ var (
 func DryRunCreate(objBytes []byte, namespace string) ([]byte, error) {
 	config, err := GetKubeConfig()
 	if err != nil {
-		return nil, fmt.Errorf("Error in getting K8s config; %s", err.Error())
+		return nil, fmt.Errorf("Error in getting k8s config; %s", err.Error())
 	}
 	dyClient, err := dynamic.NewForConfig(config)
 	if err != nil {
@@ -88,7 +88,7 @@ func DryRunCreate(objBytes []byte, namespace string) ([]byte, error) {
 func StrategicMergePatch(objBytes, patchBytes []byte, namespace string) ([]byte, error) {
 	config, err := GetKubeConfig()
 	if err != nil {
-		return nil, fmt.Errorf("Error in getting K8s config; %s", err.Error())
+		return nil, fmt.Errorf("Error in getting k8s config; %s", err.Error())
 	}
 	dyClient, err := dynamic.NewForConfig(config)
 	if err != nil {
@@ -144,7 +144,7 @@ func StrategicMergePatch(objBytes, patchBytes []byte, namespace string) ([]byte,
 func GetApplyPatchBytes(objBytes []byte, namespace string) ([]byte, []byte, error) {
 	config, err := GetKubeConfig()
 	if err != nil {
-		return nil, nil, fmt.Errorf("Error in getting K8s config; %s", err.Error())
+		return nil, nil, fmt.Errorf("Error in getting k8s config; %s", err.Error())
 	}
 	dyClient, err := dynamic.NewForConfig(config)
 	if err != nil {