Validator quality update

[vkresch]

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No issue just improving the quality.

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Change notes PR

• update the osi submodule with the new regex for rules
• adds a custom generated trace file with 50 message from the documentation for validation test
• removed version definition from PyYaml since later versions does not have the method Fullloader
• added black code formatter to CI and formatted the actual code with it
• added vulture to the CI to search for dead unused code
• removed redundant code and unnecessary folder pyosi

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@jdsika pls review :)

Check the checklist

• My code and comments follow the contributors guidelines of this project.
• I have performed a self-review of my own code.
• I have made corresponding changes to the documentation for osi-validation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests / travis ci pass locally with my changes.