vaultlocker really need more debug logging

[Adam Dyess]

https://github.com/juju/charm-helpers/blob/348506e1eaa04478f59eab227146799941dd34f1/charmhelpers/contrib/openstack/vaultlocker.py#L81

This is really quite a block box. When looking for incomplete context data, the final solution was that i couldn't retrieve a token at this line.

Please add more debugging than a comment "Try Next"

                    try:
                        secret_id = retrieve_secret_id(
                            url=vault_url,
                            token=token
                        )
                        token_success = True
                    except hvac.exceptions.InvalidRequest as e:
                        # Try next
                        log("Token {} was unsuccessful (e)".format(token, e)

This block would REALLY help track down why the vault relation was unsuccessful.

In the end the work around was to refresh-secrets in the vault/leader