APP_PATH check

[danwos]

groundwork.py:61

If APP_PATH is relative, a path gets calculated.
But there is no final check, if the calucalated path exists.

self.path = self.config.get("APP_PATH", None)
        if self.path is None:
            self.path = os.getcwd()
        elif not os.path.isabs(self.path):
            self.path = os.path.abspath(self.path)
            self.log.warning("Given APP_PATH is relative, calculated following, absolute path: %s" % self.path)
        elif not os.path.exists(self.path):
            raise IOError("Given APP_PATH does not exist: %s" % self.path)

The last elif should be executed everytime.