Add mtodd to contributors

contributors.md

@@ -81,3 +81,4 @@ Thank you to all contributors:
 * [Matthieu Tardy](https://github.com/c0riolis)
 * [michaelian ennis](https://github.com/mennis)
 * [Amitay Stern](https://github.com/amist)
+* [Matt Todd](https://github.com/mtodd)