Merge pull request kubernetes#3606 from SergeyKanzhelev/nodeSwapIsAlpha

node swap is alpha (fixing mistake in kep.yaml)

Author: k8s-ci-robot

keps/sig-node/2400-node-swap/kep.yaml

@@ -18,7 +18,7 @@ approvers:
   - "@dchen1107"
 
 # The target maturity stage in the current dev cycle for this KEP.
-stage: beta
+stage: alpha
 
 # The most recent milestone for which work toward delivery of this KEP has been
 # done. This can be the current (upcoming) milestone, if it is being actively