Add standard measure support to the get schema versions request.
Log DPU exceptions.
Update DPU runner to support standard measures.
Add a MongoDataSet deleteData method and fix the date bounds on the getData
method.
Delete previous DPU output data before running a DPU.
Change min_num_to_return to include_one_previous like it should have
been all along.
Put the previous point in the right place.
Adding DPU params and output schema IDs.
Adding 2 fake schemas to help with testing.