Update d3js.org on postpublish.

package.json

@@ -27,7 +27,8 @@
   "scripts": {
     "pretest": "mkdir -p build && rollup -c -o build/d3.js -- index.js",
     "test": "faucet `find test -name '*-test.js'`",
-    "prepublish": "npm run test && uglifyjs build/d3.js -c -m -o build/d3.min.js && rm -f build/d3.zip && zip -j build/d3.zip -- LICENSE README.md build/d3.js build/d3.min.js"
+    "prepublish": "npm run test && uglifyjs build/d3.js -c -m -o build/d3.min.js && rm -f build/d3.zip && zip -j build/d3.zip -- LICENSE README.md build/d3.js build/d3.min.js",
+    "postpublish": "VERSION=`node -e 'console.log(require(\"./package.json\").version)'`; cp -v build/d3.js ../d3.github.com/d3.v${VERSION}.js && cp -v build/d3.min.js ../d3.github.com/d3.v${VERSION}.min.js && cd ../d3.github.com && git add d3.v${VERSION}.js d3.v${VERSION}.min.js && git commit -m \"Add d3 v${VERSION}.\" && git push"
   },
   "devDependencies": {
     "faucet": "0.0",