Add placeholder-name CLI

- main and unit tests for main
- client package to be done in a future commit

Signed-off-by: Aram Price <pricear@vmware.com>

pkg/client/client.go

@@ -0,0 +1,15 @@
+/*
+Copyright 2020 VMware, Inc.
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package client
+
+import "k8s.io/client-go/pkg/apis/clientauthentication"
+
+func ExchangeToken(token, caBundle, apiEndpoint string) (*clientauthentication.ExecCredential, error) {
+	_ = token
+	_ = caBundle
+	_ = apiEndpoint
+	return nil, nil
+}