add sgleadow contributor

Author: dherault

package.json

@@ -73,6 +73,7 @@
     "Shaun (https://github.com/starsprung)",
     "Shine Li (https://github.com/shineli)",
     "Stefan Siegl (https://github.com/stesie)",
+    "Stewart Gleadow (https://github.com/sgleadow)",
     "Tuan Minh Huynh (https://github.com/tuanmh)",
     "Utku Turunc (https://github.com/utkuturunc)",
     "Vasiliy Solovey (https://github.com/miltador)"