refactor: use relative path that stays inside folder (#199)

Currently this path extends outside the root contract folder path, which could cause issues with tools that expect to use this tools from within the `src` path

Co-authored-by: marktoda <toda.mark@gmail.com>

src/AllowanceTransfer.sol

@@ -6,7 +6,7 @@ import {SafeTransferLib} from "solmate/src/utils/SafeTransferLib.sol";
 import {PermitHash} from "./libraries/PermitHash.sol";
 import {SignatureVerification} from "./libraries/SignatureVerification.sol";
 import {EIP712} from "./EIP712.sol";
-import {IAllowanceTransfer} from "../src/interfaces/IAllowanceTransfer.sol";
+import {IAllowanceTransfer} from "./interfaces/IAllowanceTransfer.sol";
 import {SignatureExpired, InvalidNonce} from "./PermitErrors.sol";
 import {Allowance} from "./libraries/Allowance.sol";