code: def default_login_checker(user):
      
      username = user.get('username')
      password = user.get('password')
      the_username = os.environ.get(
          'SIMPLELOGIN_USERNAME',
          current_app.config.get('SIMPLELOGIN_USERNAME', 'admin')
      )
      the_password = os.environ.get(
          'SIMPLELOGIN_PASSWORD',
          current_app.config.get('SIMPLELOGIN_PASSWORD', 'secret')
      )
      if username == the_username and password == the_password:
          return True
      return False
docs: user must be a dictionary here default is
      checking username/password
      if login is ok returns True else False
  
      :param user: dict {'username':'', 'password': ''}