Add mrbobbytables to github admins team

calebamiles has graciously agreed to step down to make room

github-management/OWNERS

@@ -5,7 +5,6 @@ approvers:
   - spiffxp
 
 reviewers:
-  - calebamiles
   - fejta
   - idvoretskyi
   - justaugustus

github-management/README.md

@@ -28,7 +28,7 @@ various tasks.
 
 This team (**[@kubernetes/owners](https://github.com/orgs/kubernetes/teams/owners)**) is as follows:
 * Aaron Crickenberger (**[@spiffxp](https://github.com/spiffxp)**, US Pacific)
-* Caleb Miles (**[@calebamiles](https://github.com/calebamiles)**, US Pacific)
+* Bob Killen (**[@mrbobbytables](https://github.com/mrbobbytables)**, US Eastern)
 * Christoph Blecker (**[@cblecker](https://github.com/cblecker)**, CA Pacific)
 * Erick Fejta (**[@fejta](https://github.com/fejta)**, US Pacific)
 * Nikhita Raghunath (**[@nikhita](https://github.com/nikhita)**, Indian Standard Time)