This README should help to inspire people to run this themselves. It
will introduce people on how to set this up and provide a nice
integration with their GitLab instance.
GitLab provides the API URL as a predefined enviornment variables for
each CI job. Therefore adding it to the config and using it there seems
very useful. It should also improve the protability of the repository.
Due to the incomplete entrypoint, bash doesn't want to execute scripts.
The error message it provides says:
```
/bin/sh: /bin/sh: cannot execute binary file
```
The solution is rather trivial by making the entrypoint `["/bin/bash",
"-c"]`.
