Show correct lines of code badge

Author: awinkler

README.md

@@ -7,7 +7,7 @@
 [![Build Status](http://build.ros.org/buildStatus/icon?job=Mdev__towr__ubuntu_bionic_amd64)](http://build.ros.org/view/Mdev/job/Mdev__towr__ubuntu_bionic_amd64/)
 [![Documentation](https://img.shields.io/badge/docs-generated-brightgreen.svg)](http://docs.ros.org/kinetic/api/towr/html/)
 [![ROS hosting](https://img.shields.io/badge/ROS-integration-blue.svg)](http://wiki.ros.org/towr)
-![](https://tokei.rs/b1/github/ethz-adrl/towr)
+![](https://tokei.rs/b1/github/ethz-adrl/towr?category=code)
 [![CodeFactor](https://www.codefactor.io/repository/github/ethz-adrl/towr/badge)](https://www.codefactor.io/repository/github/ethz-adrl/towr)
 [![License BSD-3-Clause](https://img.shields.io/badge/license-BSD--3--Clause-blue.svg)](https://tldrlegal.com/license/bsd-3-clause-license-%28revised%29#fulltext)