Add blue deploy button (vercel#99)

README.md

@@ -61,7 +61,7 @@ You'll want to fork this repository and deploy your own image generator.
 
 Alternatively, you can do a one-click to deploy with the button below.
 
-[![Deploy to now](https://deploy.now.sh/static/button.svg)](https://zeit.co/new/project?template=zeit/og-image)
+[![Deploy to now](https://zeit.co/button)](https://zeit.co/new/project?template=zeit/og-image)
 
 Once you have an image generator that sparks joy, you can setup [automatic Now + GitHub](https://zeit.co/github) deployments so that pushing to master is also deploying to production! 🚀