Add support for upsert

[sdeframond]

Adding support for upsert would save an API call in some use cases. It should maybe be called find_or_create and follow ActiveRecord semantics. Restforce supports upsert.

Is anyone else interested? Was this already discussed?

[eloyesp]

It sounds good, but I would not use find_or_create because upsert follows different rules, so it might create confusion. Find_by accepts complex conditions, while upsert only uses a single value.

I think that an upsert class method in sobject (quite similar to create) could do the trick.