Add a script for generating CA signed certs, and a client cert.

@filbranden @jbeda Take a look.  @derekwaynecarr is there an easy way to get the IP address on a vagrant cluster?
You can detect your external IP with 

```
dig +short @ns1.google.com. o-o.myaddr.google.com. txt
```

This is a pretty arcane but that works pretty much anywhere.  Ironically, the only place it doesn't work is when you are on google's corp network.

For GCE, you can use the v1 metadata interface:
```
curl -H Metadata-Flavor:Google http://metadata.google.internal./computeMetadata/v1/instance/network-interfaces/0/access-configs/0/external-ip
```