#### Expected Behavior Supports [findiff](https://github.com/maroba/findiff) #### Actual Behavior Does not support findiff #### Checklist - [x] I have completely filled out this template - [x] I have confirmed that this issue exists on the current `master` branch - [x] I have confirmed that this is not a duplicate issue by searching [issues](https://github.com/QuantConnect/Lean/issues)