CHANGELOG
* Add support for environment variable WHITELIST_ALL_TOKENS. If set (to any value), the whitelist will be set to '*'.
* Add the sorting of bids/asks for the GET /v2/orderbook endpoint as stated in the SRA v2:
https://github.com/0xProject/standard-relayer-api/blob/master/http/v2.md#get-v2orderbook
* Fix bug where orders in DB weren't being added to OrderWatcher on re-start
* Fix bug where order fillability wasn't being checked before being added to OrderWatcher & the database