[chore] Added backers and sponsors on the README (#2933)

Readme.md

@@ -1,6 +1,7 @@
 
 # socket.io
 
+[![Backers on Open Collective](https://opencollective.com/socketio/backers/badge.svg)](#backers) [![Sponsors on Open Collective](https://opencollective.com/socketio/sponsors/badge.svg)](#sponsors)
 [![Build Status](https://secure.travis-ci.org/socketio/socket.io.svg?branch=master)](https://travis-ci.org/socketio/socket.io)
 [![Dependency Status](https://david-dm.org/socketio/socket.io.svg)](https://david-dm.org/socketio/socket.io)
 [![devDependency Status](https://david-dm.org/socketio/socket.io/dev-status.svg)](https://david-dm.org/socketio/socket.io#info=devDependencies)
@@ -163,6 +164,79 @@ Set the environmental variable `TEST_VERSION` to `compat` to test the transpiled
 
 The `gulp` task `test` will always transpile the source code into es5 and export to `dist` first before running the test.
 
+
+## Backers
+
+Support us with a monthly donation and help us continue our activities. [[Become a backer](https://opencollective.com/socketio#backer)]
+
+<a href="https://opencollective.com/socketio/backer/0/website" target="_blank"><img src="https://opencollective.com/socketio/backer/0/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/1/website" target="_blank"><img src="https://opencollective.com/socketio/backer/1/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/2/website" target="_blank"><img src="https://opencollective.com/socketio/backer/2/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/3/website" target="_blank"><img src="https://opencollective.com/socketio/backer/3/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/4/website" target="_blank"><img src="https://opencollective.com/socketio/backer/4/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/5/website" target="_blank"><img src="https://opencollective.com/socketio/backer/5/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/6/website" target="_blank"><img src="https://opencollective.com/socketio/backer/6/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/7/website" target="_blank"><img src="https://opencollective.com/socketio/backer/7/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/8/website" target="_blank"><img src="https://opencollective.com/socketio/backer/8/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/9/website" target="_blank"><img src="https://opencollective.com/socketio/backer/9/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/10/website" target="_blank"><img src="https://opencollective.com/socketio/backer/10/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/11/website" target="_blank"><img src="https://opencollective.com/socketio/backer/11/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/12/website" target="_blank"><img src="https://opencollective.com/socketio/backer/12/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/13/website" target="_blank"><img src="https://opencollective.com/socketio/backer/13/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/14/website" target="_blank"><img src="https://opencollective.com/socketio/backer/14/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/15/website" target="_blank"><img src="https://opencollective.com/socketio/backer/15/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/16/website" target="_blank"><img src="https://opencollective.com/socketio/backer/16/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/17/website" target="_blank"><img src="https://opencollective.com/socketio/backer/17/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/18/website" target="_blank"><img src="https://opencollective.com/socketio/backer/18/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/19/website" target="_blank"><img src="https://opencollective.com/socketio/backer/19/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/20/website" target="_blank"><img src="https://opencollective.com/socketio/backer/20/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/21/website" target="_blank"><img src="https://opencollective.com/socketio/backer/21/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/22/website" target="_blank"><img src="https://opencollective.com/socketio/backer/22/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/23/website" target="_blank"><img src="https://opencollective.com/socketio/backer/23/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/24/website" target="_blank"><img src="https://opencollective.com/socketio/backer/24/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/25/website" target="_blank"><img src="https://opencollective.com/socketio/backer/25/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/26/website" target="_blank"><img src="https://opencollective.com/socketio/backer/26/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/27/website" target="_blank"><img src="https://opencollective.com/socketio/backer/27/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/28/website" target="_blank"><img src="https://opencollective.com/socketio/backer/28/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/backer/29/website" target="_blank"><img src="https://opencollective.com/socketio/backer/29/avatar.svg"></a>
+
+
+## Sponsors
+
+Become a sponsor and get your logo on our README on Github with a link to your site. [[Become a sponsor](https://opencollective.com/socketio#sponsor)]
+
+<a href="https://opencollective.com/socketio/sponsor/0/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/0/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/1/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/1/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/2/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/2/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/3/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/3/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/4/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/4/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/5/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/5/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/6/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/6/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/7/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/7/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/8/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/8/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/9/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/9/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/10/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/10/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/11/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/11/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/12/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/12/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/13/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/13/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/14/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/14/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/15/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/15/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/16/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/16/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/17/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/17/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/18/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/18/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/19/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/19/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/20/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/20/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/21/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/21/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/22/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/22/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/23/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/23/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/24/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/24/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/25/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/25/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/26/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/26/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/27/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/27/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/28/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/28/avatar.svg"></a>
+<a href="https://opencollective.com/socketio/sponsor/29/website" target="_blank"><img src="https://opencollective.com/socketio/sponsor/29/avatar.svg"></a>
+
+
 ## License
 
 [MIT](LICENSE)