Merge pull request #4957 from kannon92/mark-size-backed-memory-implemented

[KEP-1967]: mark as implemented

Author: k8s-ci-robot

keps/sig-node/1967-size-memory-backed-volumes/kep.yaml

@@ -6,7 +6,7 @@ authors:
 owning-sig: sig-node
 participating-sigs:
   - sig-storage
-status: implementable
+status: implemented
 creation-date: 2020-09-03
 reviewers:
   - "@dashpole"