Add CSI logo

Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

Author: caniszczyk

README.md

@@ -1,4 +1,7 @@
 # Container Storage Interface (CSI) Specification [![build status](https://travis-ci.org/container-storage-interface/spec.svg?branch=master)](https://travis-ci.org/container-storage-interface/spec)
+
+![CSI Logo](logo.png)
+
 This project contains the CSI [specification](spec.md). Please see the
 [build reference](#build-reference) section for information on how to
 generate the protobuf or Go source files.