v1.2: Fix IDA and fee calculation issues (#6)

* sushiswap oracle, tellor fallback, events

* update tests and readme

* eth->dai exchange testing

* check IDA shares before distribute

* misc. fixes for deploy

* Added notes for v2 spec

* calculate fee and distribute the actualAmount

* tests for fee and v1.2 deploy config

* script for setting rate tolerance

* support verification