Upgraded review-bot to version 2.0.1 (#1784)

## [Updated review bot
version](https://github.com/paritytech/polkadot-sdk/commit/677610ba)

updated version to version `2.0.1` which contains
https://github.com/paritytech/review-bot/pull/90, a fix for the team
members not being fetch in its totality.

## [Updated review-bot.yml minApprovals
convention](https://github.com/paritytech/polkadot-sdk/commit/b1446832)

Renamed `min_approvals` to `minApprovals`. A breaking change in
https://github.com/paritytech/review-bot/pull/86 which was done to
standarize all the cases (so now everything is camelCase)