Add Jason to official contributors list.

package.json

@@ -15,6 +15,12 @@
     "name": "Mike Bostock",
     "url": "http://bost.ocks.org/mike"
   },
+  "contributors": [
+    {
+      "name": "Jason Davies",
+      "url": "http://jasondavies.com"
+    }
+  ],
   "repository": {
     "type": "git",
     "url": "https://github.com/mbostock/d3.git"

src/package.js

@@ -17,6 +17,12 @@ console.log(JSON.stringify({
     "name": "Mike Bostock",
     "url": "http://bost.ocks.org/mike"
   },
+  "contributors": [
+    {
+      "name": "Jason Davies",
+      "url": "http://jasondavies.com"
+    }
+  ],
   "repository": {
     "type": "git",
     "url": "https://github.com/mbostock/d3.git"