📝 updating readme file

added pytest passing badge to readme file

README.md

@@ -1,6 +1,8 @@
 # vetting
 
-`vetting` contains simple, stand-alone Python tools for vetting transiting signals in NASA's Kepler, K2 and TESS data. `vetting` requires an installation of Python 3.8 or higher.
+**`vetting` contains simple, stand-alone Python tools for vetting transiting signals in NASA's Kepler, K2 and TESS data. `vetting` requires an installation of Python 3.8 or higher.**
+
+![pytest](https://github.com/ssdatalab/vetting/workflows/pytest/badge.svg)
 
 ## Installation