Add deprecation warnings for Helm 2 (#127)

* Add deprecation warnings for Helm 2

* helm storage will be deprecated with helm 2

* Fix e2e tests

README.md

@@ -95,6 +95,7 @@ cert-manager/cert-manager-webhook            cert-manager            MutatingWeb
 This indicates that the StatefulSet audit-dashboard-prod-rabbitmq-ha was deployed with apps/v1beta1 which is deprecated in 1.16
 
 You can also use Pluto with helm 2:
+**DEPRECATION WARNING** - Helm 2 will deprecated in November of 2020. Please see [here](https://helm.sh/blog/helm-v2-deprecation-timeline/) for more information.
 
 ```
 $ pluto detect-helm --helm-version=2 -A

cmd/root.go

@@ -71,9 +71,9 @@ func init() {
 	detectFilesCmd.PersistentFlags().StringVarP(&directory, "directory", "d", "", "The directory to scan. If blank, defaults to current working dir.")
 
 	rootCmd.AddCommand(detectHelmCmd)
-	detectHelmCmd.PersistentFlags().StringVar(&helmVersion, "helm-version", "3", "Helm version in current cluster (2|3)")
+	detectHelmCmd.PersistentFlags().StringVar(&helmVersion, "helm-version", "3", "Helm version in current cluster (2|3). WARNING: will be deprecated in a near release.")
 	detectHelmCmd.PersistentFlags().StringVarP(&namespace, "namespace", "n", "", "Only detect releases in a specific namespace.")
-	detectHelmCmd.PersistentFlags().StringVar(&helmStore, "helm-store", "configmaps", "Helm storage for v2 (configmaps|secrets)")
+	detectHelmCmd.PersistentFlags().StringVar(&helmStore, "helm-store", "configmaps", "Helm storage for v2 (configmaps|secrets). WARNING: will be deprecated in a near release.")
 
 	rootCmd.AddCommand(listVersionsCmd)
 	rootCmd.AddCommand(detectCmd)

e2e/tests/02_helm-detect-2.yaml

@@ -23,7 +23,7 @@ testcases:
   - script: pluto detect-helm --helm-version=2 --target-versions k8s=v1.16.0 --components cert-manager
     assertions:
     - result.code ShouldEqual 0
-    - result.systemout ShouldEqual "No output to display"
+    - result.systemout ShouldContainSubstring "No output to display"
 
 - name: helm2 detect wide namespaced secrets
   steps:

pkg/helm/helm.go

@@ -73,6 +73,8 @@ func (h *Helm) FindVersions() error {
 
 	switch h.Version {
 	case "2":
+		fmt.Println("DEPRECATION WARNING: Helm 2 will be deprecated very soon. Please migrate.")
+		fmt.Println("please see https://helm.sh/blog/helm-v2-deprecation-timeline/ for more info")
 		err = h.getReleasesVersionTwo()
 	case "3":
 		err = h.getReleasesVersionThree()