add David Wimsey to the contributor list
diff --git a/README.markdown b/README.markdown
index d0963a8..19ad520 100644
--- a/README.markdown
+++ b/README.markdown
@@ -242,6 +242,7 @@
 * Tom Graves ([@tgravescs](https://github.com/tgravescs))
 * Dror Weiss ([@drorweiss](https://github.com/drorweiss))
 * Victor Wong ([@victor-wong](https://github.com/victor-wong))
+* David Wimsey ([@dwimsey](https://github.com/dwimsey))
 
 ## Acknowledgements