Example fix

The way the example currently works is a bit confusing (and breaks on windows). If you run ./bin/skadi on windows, it fails, as the ./bin directory will be added to the python path, and when the example calls `from skadi import etc....`, the example file will be imported instead of the skadi package. Changing the name of the file fixes this.

I also changed the way that the `path` var is created, so it no longer requires the demo file be in the skadi base directory. This means it works in the same way as a standard utility now.