Merge branch 'v3-beta' of github.com:zeit/next.js into v3-beta

package.json

 {
   "name": "next",
-  "version": "3.0.1-beta.10",
+  "version": "3.0.1-beta.12",
   "description": "Minimalistic framework for server-rendered React applications",
   "main": "./dist/server/next.js",
   "license": "MIT",