Rust pop-quiz: average price

Rust pop-quiz: average price.

You recall trader.rs 

2 complications:

1. The input data is enriched with additional fields. Update trader to ignore those new fields.

2. For each asset-type, print the running total and average price per token.

DO-it! TO-it! 

Where are we going with this?

PnL ('profit 'n loss') per trade, then PnL per day.

A new metric for my @TeamKujira FIN order book trading efficacy.

• (answer)