chore: update contributors

Author: daviddias

package.json

@@ -69,6 +69,7 @@
   "contributors": [
     "David Dias <daviddias.p@gmail.com>",
     "Francisco Baio Dias <xicombd@gmail.com>",
+    "Richard Littauer <richard.littauer@gmail.com>",
     "Stephen Whitmore <stephen.whitmore@gmail.com>",
     "dignifiedquire <dignifiedquire@gmail.com>",
     "greenkeeperio-bot <support@greenkeeper.io>",