Make Codacy happy

[nrybowski]

Codacy is an online platform running, among others, a set of linters on each file of the codebase.
Hence, it discovers various code styling and security issues whose severity varies from minor to critical.

Generally speaking, those issues are not hard to fix but the process may be time-consuming.
So, they are by nature "Good First Issues" and a good way to get a foothold in the project.

The current code quality is indicated by this little badge .