You should be working in a fork, see the following documentation
On the
masterbranch
$ git fetch --all
$ git rebase upstream/master$ git checkout -b reason-for-changes$ composer installIn the root directory, you can run the test suite by running:
$ vendor/bin/phpunit $ git add [files...]
$ git commit -m "DESCRIPTION OF CHANGES"
$ git push origin masterTo contribute your changes back, simply perform a Pull Request against the master branch.