How to analyze a GitHUB repository for the number of unit tests?

Question

GitHub

The task was to motivate programmers to write unit tests. I thought that I could go from the side of the carrot and praise in some way the one who wrote them the most in a sprint.
The rake suddenly found how to analyze the repository for the presence of these very unit tests and, if possible, show the graph? Are there ready-made solutions?

Answer 1

https://coveralls.io/
https://www.codacy.com/