update readme

Author: source-c

README.adoc

@@ -11,7 +11,7 @@ Add the following to your http://github.com/technomancy/leiningen[Leiningen's] `
 
 [source,clojure]
 ----
-[net.tbt-post/zlib-tiny "0.2.3"]
+[net.tbt-post/zlib-tiny "0.2.5"]
 ----
 
 [source, clojure]
@@ -64,7 +64,7 @@ $ lein install
 
 == License
 
-Copyright © 2017-2018
+Copyright © 2017-2021
 
 Distributed under the http://www.apache.org/licenses/LICENSE-2.0[Apache License v 2.0]