Remove Authorized from Marketplace redeemVaultInterest

[JTraversa]

In order to allow us to claim any nToken interest generated by the fees accrued to Swivel.sol, we need to be able to arbitrarily redeem Swivel.sol's vault interest.

To do this, all we need to do is remove the authorized modifier from the function on marketplace.

[JTraversa]

Needs review, probably best not to remove that authorized modifier, and to instead add a 2nd method