Add FOSSA status badge

Signed-off-by: Bassam Tabbara <bassam@upbound.io>

README.md

@@ -3,6 +3,7 @@
 [![Build Status](https://jenkins.rook.io/buildStatus/icon?job=rook/rook/master)](https://jenkins.rook.io/blue/organizations/jenkins/rook%2Frook/activity)
 [![GitHub release](https://img.shields.io/github/release/rook/rook/all.svg?style=flat-square)](https://github.com/rook/rook/releases)
 [![Go Report Card](https://goreportcard.com/badge/github.com/rook/rook)](https://goreportcard.com/report/github.com/rook/rook)
+[![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Frook%2Frook.svg?type=shield)](https://app.fossa.io/projects/git%2Bgithub.com%2Frook%2Frook?ref=badge_shield)
 [![Slack](https://rook-slackin.herokuapp.com/badge.svg)](https://rook-slackin.herokuapp.com/badge.svg)
 [![Twitter Follow](https://img.shields.io/twitter/follow/rook_io.svg?style=social&label=Follow)](https://twitter.com/intent/follow?screen_name=rook_io&user_id=788180534543339520)
 
@@ -40,3 +41,5 @@ Please use the following to reach members of the community:
 ## Licensing
 
 Rook is under the Apache 2.0 license.
+
+[![FOSSA Status](https://app.fossa.io/api/projects/git%2Bgithub.com%2Frook%2Frook.svg?type=large)](https://app.fossa.io/projects/git%2Bgithub.com%2Frook%2Frook?ref=badge_large)