Existence of Facebook Profile

[cmlh]

Confirm the existence of Facebook Profile (i.e. it might have been deleted in during the last execution of the Transform) and if it is no longer available throw a Partial Error.

[cmlh]

The sub facebook_graphapi_down() will need to be modified as it is executed when HTTP Status Code 400 (Bad Request) is returned when the Facebook User Profile is inactive and hence does not have a Cover Image.