Updating Author names and emails (correct email for Curtis, adding Guysung)

composer.json

@@ -7,9 +7,13 @@
             "name": "Rob Napier",
             "email": "robnapier@gmail.com"
         },
+        {
+            "name": "Guysung Kim",
+            "email": "guysung.kim@gmail.com"
+        },
         {
             "name": "Curtis Farnham",
-            "email": "curtisdf@gmail.com"
+            "email": "curtisfarnham@gmail.com"
         }
     ],
     "require": {