retry classification on api / network failure

[camallen]

Looks like it just errors out on failed classification submit. Probably best to import functionality like this, zooniverse/Panoptes-Front-End#1787

Finally could be related to talk dups that didn't make it to the classification api save methods (so the data isn't in the db and the subject gets shown to the user again).

[aliburchard]

https://www.zooniverse.org/projects/zooniverse/wildcam-gorongosa/talk/79/7125