Merge pull request #794 from cybozu-go/bump-1.31.0-rc.1

Bump version to 1.31.0-rc.1

Author: chez-shanpu

version.go

@@ -1,7 +1,7 @@
 package cke
 
 // Version represents current cke version
-const Version = "1.30.6"
+const Version = "1.31.0-rc.1"
 
 // ConfigVersion represents the current configuration scheme
 // of how CKE constructs its Kubernetes cluster.