Added readme image

it needs to be added to the repo or something later.

README.md

+![](https://ipfs.io/ipfs/QmVk7srrwahXLNmcDYvyUEJptyoxpndnRa57YJ11L4jV26/ipfs.go.png)
+
 # IPFS implementation in Go
 [![GoDoc](https://godoc.org/github.com/ipfs/go-ipfs?status.svg)](https://godoc.org/github.com/ipfs/go-ipfs) [![Build Status](https://travis-ci.org/ipfs/go-ipfs.svg?branch=master)](https://travis-ci.org/ipfs/go-ipfs)