[cinder] propose Lucio Seki for cinder core

Lucio Seki (lseki on IRC) has been very active this cycle doing reviews, answering questions in IRC, and participating in the Cinder weekly meetings and at the midcycles. He's been particularly thorough and helpful in his reviews of backend drivers, and has also been helpful in giving pointers to new driver maintainers who are setting up third party CI for their drivers. Having Lucio as a core reviewer will help improve the team's review bandwidth without sacrificing review quality.

In the absence of objections, I'll add Lucio to the core team just before the next Cinder team meeting (Wednesday, 16 September at 1400 UTC in #openstack-meeting-alt). Please communicate any concerns to me before that time.

cheers, brian