Add return-status-codes option.
Add return-status-codes option to README.
Update CHANGES.
Remove jenkins-code-analysis option that never has been used.
Use travis.cfg for travis.
Run code-analysis on travis.
Extend the parts.
Fix travis script section.
Make sure flake8.log is written when jenkins flag is set.
Just run flake8 on p.a.codeanalysis.
Remove more code-analysis options from travis build.
Set flake8-max-complexity to 20.