Bump version to 1.4.0.2 (#3190)

lib/mastodon/version.rb

@@ -9,15 +9,15 @@ module Mastodon
     end
 
     def minor
-      3
+      4
     end
 
     def patch
-      2
+      0
     end
 
     def pre
-      nil
+      2
     end
 
     def to_a