[README] Add license badge to make licensing clear + Coverity badge

README.md

 Pinocchio
 ===========
+[![License LGPL 3][badge-license]](http://www.gnu.org/licenses/lgpl-3.0.txt)
 [![Build Status](https://travis-ci.org/stack-of-tasks/pinocchio.svg?branch=devel)](https://travis-ci.org/stack-of-tasks/pinocchio)
 [![Coverage Status](https://coveralls.io/repos/github/stack-of-tasks/pinocchio/badge.svg?branch=devel)](https://coveralls.io/github/stack-of-tasks/pinocchio?branch=devel)
-
+[![Coverity Scan Build Status](https://scan.coverity.com/projects/7824/badge.svg)](https://scan.coverity.com/projects/pinocchio)
 
 **Warning:** This repository contains [Git
 submodules][git-submodules]. Please clone this repository using the