Mention Gratipay in the README

README.md

@@ -2,6 +2,7 @@
 [![MELPA](http://melpa.org/packages/projectile-badge.svg)](http://melpa.org/#/projectile)
 [![MELPA Stable](http://stable.melpa.org/packages/projectile-badge.svg)](http://stable.melpa.org/#/projectile)
 [![Build Status](https://travis-ci.org/bbatsov/projectile.png?branch=master)](https://travis-ci.org/bbatsov/projectile)
+[![Gratipay Team](https://img.shields.io/gratipay/team/projectile.svg?maxAge=2592000)](https://gratipay.com/projectile/)
 
 ## Synopsis
 
@@ -48,7 +49,11 @@ Here's a glimpse of Projectile in action:
 
 ![Projectile Screenshot](doc/screenshots/projectile.png)
 
-You can support my work on Projectile via [Salt](https://salt.bountysource.com/teams/projectile).
+You can support my work on Projectile via
+ [Salt](https://salt.bountysource.com/teams/projectile) and
+ [Gratipay](https://www.gratipay.com/projectile).
+
+[![Support via Gratipay](https://cdn.rawgit.com/gratipay/gratipay-badge/2.1.3/dist/gratipay.png)](https://gratipay.com/projectile)
 
 ## Quickstart