bumping django to 2.2.21 Signed-off-by: vsoch <vsoch@users.noreply.github.com>

bumping django again Signed-off-by: vsoch <vsoch@users.noreply.github.com>

adding note to README about folder permissions Signed-off-by: Vanessa Sochat <vsochat@stanford.edu>

updating CHANGELOG 

updating README