README: Change latest version v0.6

Author: aperezdc

README.md

@@ -3,7 +3,7 @@ lua-wcwidth
 
 [![Build Status](https://github.com/aperezdc/lua-wcwidth/actions/workflows/build.yml/badge.svg)](https://github.com/aperezdc/lua-wcwidth/actions/workflows/build.yml)
 [![Coverage Status](https://coveralls.io/repos/github/aperezdc/lua-wcwidth/badge.svg?branch=master)](https://coveralls.io/github/aperezdc/lua-wcwidth?branch=master)
-[![LuaRocks](https://img.shields.io/badge/luarocks-v0.5-blue.png)](https://luarocks.org/modules/aperezdc/wcwidth)
+[![LuaRocks](https://img.shields.io/badge/luarocks-v0.6-blue.png)](https://luarocks.org/modules/aperezdc/wcwidth)
 
 When writing output to a fixed-width output system (such as a terminal), the
 displayed length of a string does not always match the number of characters