[neutron] Resignation announcement of Nate, Hongbin and Takashi

Hello all:

Today I would like to announce that Nate Johnston, Takashi Yamamoto and Hongbin Lu are stepping down as Neutron core reviewers and Neutron drivers. Before sending this email, I contacted them and Nate and Takashi agreed on this decision; I tried twice to contact Hongbin with no response.

In order to have a participative Neutron community, the Neutron core and Neutron drivers teams should be made up of active members in code reviews, meeting attendance and spec reviewal. Nate, Takashi and Hongbin have been very active and valuable members of the Neutron (and OpenStack) community in the past; for that I would like to thank you for your contributions.

Tomorrow I'll update the Launchpad and gerrit groups.

Regards.