sell fill timestamp incorrect

[dfelton]

trade_repeater_archive.sell_fill_timestamp seems to occasionally get incorrect values. Observed this column getting populated with the 2nd to last transaction of an order in it's corresponding trade_history_* table.

Suspect that the job responsible for filling this column is sometimes running into a race condition with the trade-history:logger job it needs for the data.

A more reliable approach would be if the repeater:archiver:fill-time job were to query the exchange for the order status, have the exchange include transactions in it's response back (a feature added to Gemini's API since this aspect of the kobens-gemini app was written), and use this information rather than relying on our history table to be up to date.