'Logs all environment variables using the given log level.
Environment variables are also returned the same way as with
`Get Environment Variables` keyword.
New in Robot Framework 2.7.'

def log_environment_variables(self, level='INFO'):

    variables = get_env_vars()
    for name in sorted(variables, key=(lambda item: item.lower())):
        self._log(('%s    =    %s' % (name, variables[name])), level)
    return variables
