update code

[karldoenitz]

• With pull requests:
  • Open your pull request against master
  • Your pull request should have no more than two commits, if not you should squash them.
  • It should pass all tests in the available continuous integrations systems such as TravisCI.
  • You should add/modify tests to cover your proposed code changes.
  • If your pull request contains a new feature, please document it on the README.