undefined download directory in postcard.py

[jpdeleon]

While following the tutorial, running
data = eleanor.TargetData(star, height=15, width=15, bkg_size=31, do_psf=True)
throws up an error in line 63:

eleanor/eleanor/postcard.py

Line 63 in 85dbc8a

'working directory instead.'.format(download_dir))

saying download_dir is not defined.

Replacing download_dir with self.post_dir temporarily solved the problem.