Fixed several pylint warnings.

* testing-pylint:
  cleaning up pylint reports
  replaced test.sh with the Jenkins version
  renamed "_utils" to "Utils"
  fixed doctest
  cleaning up pylint reports
  fixed tests after refactoring
  cleaning up pylint reports
  some refactoring and grouped the checkout function in a module
  cleaning up pylint reports
  tuning conventions for pylint
  fixed some pylint reports
  added preliminary pylint configuration file