MP-514 Update celery task to fail gracefully

@wilblack let me know if the wording on the email notification needs to be changed, along with anything else
I think your email is going to error out. The reason reason line 40 errored out is because data['description'] is not defined but you reference it in the expect. 

Change your email subject to say "update_data_topics() - could not find description for %s." % layer['name']. 

And put the web_service_url in the email body.