Add config examples for constructing clients

All the current examples rely on `config.fromKubeconfig()`. Add examples that manually specify some of the config options.

1. create a new example in [`examples/`](https://github.com/godaddy/kubernetes-client/tree/master/examples). The goal is to illustrate how to use basic auth and provide an end-to-end working example. With that in mind, the example should construct a new `client` instance using basic auth, and make an API call (*e.g.*, get Pods or Deployments) to illustrate functionality.
2. Update README.md the [More examples](https://github.com/godaddy/kubernetes-client#more-examples) section to include the new example.

Start by reviewing the existing examples/ files and the README.md More examples section to follow their client-construction and listing conventions. Add a working basic-auth example that constructs a client and makes a Pods or Deployments API call, then link it from README.md and run the example against a suitable Kubernetes API.

Written by the indexing model from the issue text.