Log Message:
py-cherrypy: updated to 18.0.0

v18.0.0
* Drop support for Python 2.7. CherryPy 17 will
  remain an LTS release for bug and security fixes.
* Drop support for Python 3.4.

v17.4.0
* When setting Response Body, reject Unicode
  values, making behavior on Python 2 same as on Python 3.
* Other inconsequential refactorings.