Merge pull request #586 from Jefftree/update-owners

Update OWNERS: prune inactive reviewers and emeritus approvers

Author: k8s-ci-robot

OWNERS

@@ -1,20 +1,13 @@
 reviewers:
-- yujuhong
-- gmarek
-- philips
-- seans3
-- apelisse
-- roycaihw
 - sttts
 - jpbetz
 - jefftree
-- alexzielenski
 approvers:
 - sttts
-- apelisse
 - jpbetz
 - jefftree
-- alexzielenski
 emeritus_approvers:
 - mbohlool
 - lavalamp
+- apelisse
+- alexzielenski