hubTransfer always returns false

[axic]

We are attempting at "verifying" the contract with Solidity's SMTChecker, which already found the following.

In https://github.com/CirclesUBI/circles-contracts/blob/master/contracts/Token.sol#L170-L172 the hubTransfer function always returns false:

    function hubTransfer(
        address from, address to, uint256 amount
    ) public onlyHub returns (bool) {
        _transfer(from, to, amount);
    }

I guess this is some remnant from some old code, the _transfer function does not return an outcome. And the only place this is called is in the Hub.transferThrough function, where its outcome is not inspected.

I have not investigated further, whether the success of each transfer is validated somehow, though the validateTransferThough suggests it should be.