[oslo] Nominating tobias-urdin for etcd3gw core

Hi team,

I raised this topic in #openstack-oslo today and already got a few acks, but I'm sending this email here for an official proposal as well as record.

The etcd3gw library is now extensively used by tooz as the primary implementation for etcd3 backend. Because Tobias is already a core reviewer in the tooz library, I propose adding him to the etcd3gw core as well.

Please let me know in case anyone has any thoughts on the proposal. I'll add him to the group next week if we hear no objections.

Thank you Takashi Kajinami