Consistent 502s hitting /schedule_a

[helgridly]

The following request is consistently 502ing for me:

https://api.open.fec.gov/v1/schedules/schedule_a/?sort=-contributor_aggregate_ytd&two_year_transaction_period=2016&api_key=MYAPIKEY

If this is as simple as adding an index to fec_fitem_sched_a.contb_aggregate_ytd I can probably open a PR, but if it'll be anything like adding an index for contb_receipt_amt I may take that offer back in a hurry :)

[jason-upchurch]

@helgridly We will look at investigating the index approach and get back to you! cc @PaulClark2

[PaulClark2]

Hussein - we are in the process of deprecating sort by contributor_aggregate_ytd, #4423. You probably received an email about this.

Sort options that may work for you to pull the data include:

Ascending

contribution_receipt_date
contribution_receipt_amount

Descending

-contribution_receipt_date
-contribution_receipt_amount