Merge pull request #98 from Z2PackDev/fix_build_badge

Change build badge to GHA

Author: greschd

README.md

@@ -9,6 +9,6 @@ A tool for creating, modifying and evaluating tight-binding models
 
 - Documentation: <https://tbmodels.greschd.ch>
 
-[![Build Status](https://travis-ci.org/Z2PackDev/TBmodels.svg?branch=dev)](https://travis-ci.org/Z2PackDev/TBmodels)
-[![Documentation Status](https://readthedocs.org/projects/tbmodels/badge/?version=latest)](https://tbmodels.greschd.ch/en/latest/?badge=latest)
+[![Continuous Integration](https://github.com/Z2PackDev/TBmodels/workflows/Continuous%20Integration/badge.svg)](https://github.com/Z2PackDev/TBmodels/actions)
+[![Documentation Status](https://readthedocs.org/projects/tbmodels/badge/?version=latest)](https://tbmodels.greschd.ch/)
 [![codecov](https://codecov.io/gh/Z2PackDev/TBmodels/branch/dev/graph/badge.svg)](https://codecov.io/gh/Z2PackDev/TBmodels)