fix(version): implement `helm version -c`, mark as hidden

Signed-off-by: Matthew Fisher <matt.fisher@microsoft.com>

cmd/helm/testdata/output/version-client-shorthand.txt

@@ -0,0 +1 @@
+version.BuildInfo{Version:"v3.0+unreleased", GitCommit:"", GitTreeState:"", GoVersion:""}

cmd/helm/testdata/output/version-client.txt

@@ -0,0 +1 @@
+version.BuildInfo{Version:"v3.0+unreleased", GitCommit:"", GitTreeState:"", GoVersion:""}

cmd/helm/version.go

@@ -61,6 +61,8 @@ func newVersionCmd(out io.Writer) *cobra.Command {
 	f := cmd.Flags()
 	f.BoolVar(&o.short, "short", false, "print the version number")
 	f.StringVar(&o.template, "template", "", "template for version string format")
+	f.BoolP("client", "c", true, "display client version information")
+	f.MarkHidden("client")
 
 	return cmd
 }

cmd/helm/version_test.go

@@ -32,6 +32,14 @@ func TestVersion(t *testing.T) {
 		name:   "template",
 		cmd:    "version --template='Version: {{.Version}}'",
 		golden: "output/version-template.txt",
+	}, {
+		name:   "client",
+		cmd:    "version --client",
+		golden: "output/version-client.txt",
+	}, {
+		name:   "client shorthand",
+		cmd:    "version -c",
+		golden: "output/version-client-shorthand.txt",
 	}}
 	runTestCmd(t, tests)
 }