Fee in Cally.setFee() should be upper-bounded

[HardlyDifficult]

From BowTiedWardens in #190

[L-02] Fee in Cally.setFee() should be upper-bounded
A malicious owner or owner account compromise can set the fee very high, up to 100%, siphoning all profits from the protocol.

Consider implementing a reasonable upper limit here:

File: Cally.sol
119: function setFee(uint256 feeRate_) external onlyOwner {
120: feeRate = feeRate_;
121: }

[HardlyDifficult]

Dupe of #48

[JeeberC4]

Issue recreated with script that includes all required data.