Charli3 Developer Updates 25/10/21

Dev updates 25/10/21:

Finished
* Updated code to resolve issues raised in the audit process
* Added additional transaction time range testing for aggregation validation
* Added tests for adding/removing nodes to aggregator
In progress
* Explore Blockfrost integration
* Implement planned additional test cases to improve test coverage
* Migrate codebase to the latest release of Plutus