OWNERS: Add aronchick, idvoretskyi, and philips
OWNERS: Add aronchick, idvoretskyi, and philips

Add aronchick, idvoretskyi, and myself as the initial OWNERS as we have
been involved in the last few weeks to make this repo successful for
v1.4.

Explicitly not adding @erictune right now even though he created the
repo because he is overloaded.

kubernetes/enhancements,kubernetes/enhancements,kubernetes/enhancements