Fix error when fetching Flickr photos with location data
Fix error when fetching Flickr photos with location data

It looks like due to [ongoing Flickr issues](https://help.flickr.com/en_us/important-planned-downtime-may-22nd-2019-H1IEsxQ6N) the `place_id`s and `woeid`s for photos with location
data aren't being returned at all - not even null/empty values.

So our code is a bit more forgiving about missing keys in the location
data now.

Fixes #204

philgyford/django-ditto,philgyford/django-ditto,philgyford/django-ditto