Making overholt work with recent dependencies
  1) update of tests
     - adjust model factories to new Factory-Boy
     - enable login system for recent Flask-Login (disabled by default for tests)
     - obtain CSRF token from login form using Flask-Fillin (old method didn't work anymore)
  2) update of forms imports for new wtf
  3) update all dependencies
  4) flask.ext.<name> -> flask_<name>