release: switch to use rc branches

lib/release/versions.rb

@@ -0,0 +1,21 @@
+require_relative './base'
+
+module Release
+
+  class Versions < Release::Base
+    def valid?
+      true
+    end
+
+    def help
+      "release versions"
+    end
+
+    def execute
+      puts
+      puts show_existing_tags
+      puts
+    end
+  end
+
+end