Remove pre from version, add extra suffix variable (#11407)

lib/mastodon/version.rb

@@ -16,20 +16,20 @@ module Mastodon
       2
     end
 
-    def pre
+    def flags
-      nil
+      ''
     end
 
-    def flags
+    def suffix
       ''
     end
 
     def to_a
-      [major, minor, patch, pre].compact
+      [major, minor, patch].compact
     end
 
     def to_s
-      [to_a.join('.'), flags].join
+      [to_a.join('.'), flags, suffix].join
     end
 
     def repository