DataCamp commits to my repository on my behalf, why?
Before you can create a course, you have to log in to DataCamp and link your account to GitHub. From that moment on, DataCamp can make changes to the repositories you've linked on your behalf. For example, when you create a new course with the "Create a DataCamp Course" dialog, we will create a repository for you, and pre-fill it with a course and chapter files with several commits. That way, the build process for your course is automatically triggered and a DataCamp course results.
Another point where DataCamp commits on your behalf is for setting 'exercise keys'. These keys are meant to link your exercises in the GitHub repository and the exercises on DataCamp's databases.