- allow stakers to unstake multiple tokens
- allow stakers to stake multiple tokens
- allow stakers to check if they can stake multiple tokens
- allow stakers to check if they can unstake multiple tokens
- switch to custom errors
- get the staker balance
- remove receive check. everyone can send to this contract
- added support to whitelist contract to send funds to the staking contract
- add full test coverage
- add support to solcover
- migrate naming to RareBlocksStaking and RareBlocksSubscription
- should anyone send ether to the contract or only allow a whitelist of addresses to send ether?
- should canStake/canUnstake return 0 if the contract is paused? -> no
- should canStake check external factors like the the contract have been approved by the stakers for the token or all-tokens? -> no