Add Pytest badge to README.md

Author: Electronic-Mango

README.md

@@ -4,6 +4,7 @@
 [![Black](https://github.com/Electronic-Mango/simple-justwatch-python-api/actions/workflows/black.yml/badge.svg)](https://github.com/Electronic-Mango/simple-justwatch-python-api/actions/workflows/black.yml)
 [![Flake8](https://github.com/Electronic-Mango/simple-justwatch-python-api/actions/workflows/flake8.yml/badge.svg)](https://github.com/Electronic-Mango/simple-justwatch-python-api/actions/workflows/flake8.yml)
 [![isort](https://github.com/Electronic-Mango/simple-justwatch-python-api/actions/workflows/isort.yml/badge.svg)](https://github.com/Electronic-Mango/simple-justwatch-python-api/actions/workflows/isort.yml)
+[![Pytest](https://github.com/Electronic-Mango/simple-justwatch-python-api/actions/workflows/pytest.yml/badge.svg)](https://github.com/Electronic-Mango/simple-justwatch-python-api/actions/workflows/pytest.yml)
 [![PyPI - Version](https://img.shields.io/pypi/v/simple-justwatch-python-api)](https://pypi.org/project/simple-justwatch-python-api/)
 
 A simple unofficial JustWatch Python API which uses [`GraphQL`](https://graphql.org/) to access JustWatch data.