thesis: Leveraging Coming for designing diff contracts to automatically check pull requests

There are pull requests that follow certain patterns. For example, INRIA/spoon#4534, INRIA/spoon#4533, INRIA/spoon#4532, and INRIA/spoon#4531 migrate different test classes to JUnit 5 using very similar change patterns.

An idea is to develop a GHAction that allows developers design diff contracts in the form [Coming specifications](https://github.com/SpoonLabs/coming#change-pattern-specification). This GHAction should be triggered whenever there is PR with a specific label/tag/keyword and comment on the PR if the changes of the PR correspond to a specified diff contract.