FEATURE REQUEST: leave fewer temp files around from using kubeconfig files

[JayBeale]

We're potentially writing a new CA.CRT file every time we switch to a client cert-key pair - we could solve this with something like the following code in assignAuthenticationCertificateAndKeyToConnection() and assignServiceAccountToConnection(), but we'd need to back up the CA.CRT path whenever we switch to token again.

	// If our current authz context had a cert auth path file (i.e., if we were using a cert-key pair), delete it
	if len(info.ClientKeyPath) > 0 {
	 	os.Remove(info.CAPath)
	}