Fetch PreimageOracle from upstream

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "rvsol/lib/forge-std"]
 	path = rvsol/lib/forge-std
 	url = https://github.com/foundry-rs/forge-std
+[submodule "rvsol/lib/optimism"]
+	path = rvsol/lib/optimism
+	url = https://github.com/ethereum-optimism/optimism

rvsol/foundry.toml

@@ -4,5 +4,19 @@ out = 'out'
 libs = ['lib']
 optimizer = true
 optimizer_runs = 999999
+remappings = [
+  '@optimism/packages/contracts-bedrock=lib/optimism/packages/contracts-bedrock',
+  '@openzeppelin/contracts-upgradeable/=lib/optimism/packages/contracts-bedrock/lib/openzeppelin-contracts-upgradeable/contracts',
+  '@openzeppelin/contracts/=lib/optimism/packages/contracts-bedrock/lib/openzeppelin-contracts/contracts',
+  '@rari-capital/solmate/=lib/optimism/packages/contracts-bedrock/lib/solmate',
+  '@cwia/=lib/optimism/packages/contracts-bedrock/lib/clones-with-immutable-args/src',
+  '@lib-keccak/=lib/optimism/packages/contracts-bedrock/lib/lib-keccak/contracts/lib',
+  'safe-contracts/=lib/optimism/packages/contracts-bedrock/lib/safe-contracts/contracts',
+  'kontrol-cheatcodes/=lib/optimism/packages/contracts-bedrock/lib/kontrol-cheatcodes/src',
+  'solady/=lib/optimism/packages/contracts-bedrock/lib/solady/src',  
+
+  'forge-std/=lib/forge-std/src',
+  'ds-test/=lib/forge-std/lib/ds-test/src',
+]
 
 # See more config options https://github.com/foundry-rs/foundry/tree/master/config

rvsol/src/Step.sol

@@ -1,12 +1,13 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.13;
 
+import {IPreimageOracle} from "@optimism/packages/contracts-bedrock/src/cannon/interfaces/IPreimageOracle.sol";
 
 contract Step {
 
-    address public preimageOracle;
+    IPreimageOracle public preimageOracle;
 
-    constructor(address _preimageOracle) {
+    constructor(IPreimageOracle _preimageOracle) {
         preimageOracle = _preimageOracle;
     }