chore: remove social links (#398)

outdated and invalid; these are too hard to keep updated from here

README.md

@@ -2,9 +2,6 @@
 
 [![](https://img.shields.io/badge/made%20by-Protocol%20Labs-blue.svg?style=flat-square)](http://ipn.io)
 [![](https://img.shields.io/badge/project-IPFS-blue.svg?style=flat-square)](http://ipfs.io/)
-[![Matrix](https://img.shields.io/badge/matrix-%23ipfs%3Amatrix.org-blue.svg?style=flat-square)](https://matrix.to/#/#ipfs:matrix.org)
-[![IRC](https://img.shields.io/badge/freenode-%23ipfs-blue.svg?style=flat-square)](http://webchat.freenode.net/?channels=%23ipfs)
-[![Discord](https://img.shields.io/discord/475789330380488707?color=blueviolet&label=discord&style=flat-square)](https://discord.gg/24fmuwR)
 [![Coverage Status](https://codecov.io/gh/ipfs/go-graphsync/branch/master/graph/badge.svg)](https://codecov.io/gh/ipfs/go-graphsync/branch/master)
 [![Build Status](https://circleci.com/gh/ipfs/go-bitswap.svg?style=svg)](https://circleci.com/gh/ipfs/go-graphsync)