Flooring seconds in compoundInterest

[holyfuchs]

compoundInterest is calculating the interest rate based on floored seconds:

https://github.com/onflow/FlowCreditMarket/blob/786cfa93251ee0ebb1788e9ebebf7b35c2b22b6c/cadence/lib/FlowCreditMarketMath.cdc#L21-L39

https://github.com/onflow/FlowCreditMarket/blob/786cfa93251ee0ebb1788e9ebebf7b35c2b22b6c/cadence/contracts/FlowCreditMarket.cdc#L4557-L4565

timestamp: UFix64
If getCurrentBlock().timestamp has a resolution below 1 second (utilizing the UFix), interacting with the contract every block will result in no interest accruing.