[TripleO] Proposing Brendan Shephard and Takashi Kajinami

I'm formally proposing that we add Brendan Shephard and Takashi Kajinami to the core reviewers team for TripleO. Takashi is already considered core on puppet-tripleo, and I'm proposing we expand that to all of TripleO, and likewise for Brendan.

They both have been contributing and reviewing for a little while now, and I feel it's time to add them to the team. Please +1 or let me know any concerns before Friday June 15th. Thanks!