update authors

Author: feross

AUTHORS.md

@@ -35,5 +35,9 @@
 - ZunSThy (zunsthy@gmail.com)
 - vijayanand nandam (vijay@cybrilla.com)
 - Luigi Pinca (luigipinca@gmail.com)
+- Diego R. B (diegorbaquero@gmail.com)
+- greenkeeper[bot] (greenkeeper[bot]@users.noreply.github.com)
+- hrafnkell orri sigurdsson (hrafnkellos@gmail.com)
+- Brian Clifton (brian@clifton.me)
 
 #### Generated by bin/update-authors.sh.