roadmap: Fix link (#146)

Author: bakkegaard

Diff for: roadmap.html

@@ -27,7 +27,7 @@ <h3><a href="https://github.com/neovim/neovim/milestone/10">0.2</a></h3>
     <li>Pre-built binaries for non-Windows platforms (tentative)</li>
 </ul>
 
-<h3><a href="https://github.com/neovim/neovim/milestone/10">0.3</a></h3>
+<h3><a href="https://github.com/neovim/neovim/milestone/11">0.3</a></h3>
 
 <ul>
     <li>Lua host, lua becomes a runtime dependency, shipped with the core editor</li>