doc: add vkurchatkin as collaborator

PR-URL: https://github.com/iojs/io.js/pull/591
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>

README.md

@@ -214,6 +214,7 @@ information about the governance of the io.js project, see
 * **Jeremiah Senkpiel** ([@fishrock123](https://github.com/fishrock123)) <fishrock123@rocketmail.com>
 * **Evan Lucas** ([@evanlucas](https://github.com/evanlucas)) <evanlucas@me.com>
 * **Brendan Ashworth** ([@brendanashworth](https://github.com/brendanashworth)) <brendan.ashworth@me.com>
+* **Vladimir Kurchatkin** ([@vkurchatkin](https://github.com/vkurchatkin)) <vladimir.kurchatkin@gmail.com>
 
 Collaborators follow the [COLLABORATOR_GUIDE.md](./COLLABORATOR_GUIDE.md) in
 maintaining the io.js project.