Update rubocop coding style

[fwininger]

Proposed changes

Coding style optimisation

Types of changes

• [x] Coding style optimization

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR.

• [x] Unit tests pass locally with my changes
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I have added necessary documentation (if appropriate)

Further comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did and what alternatives you considered, etc...

[fwininger]

Hello @oliverhamboerger can you consider this PR ?