Fix .gitignore: stop tracking ignored files

backend/lib/openzeppelin-contracts/contracts/mocks/InitializableMock.sol

@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "../proxy/utils/Initializable.sol";
+
+/**
+ * @title InitializableMock
+ * @dev This contract is a mock to test initializable functionality
+ */
+contract InitializableMock is Initializable {
+    bool public initializerRan;
+    bool public onlyInitializingRan;
+    uint256 public x;
+
+    function isInitializing() public view returns (bool) {
+        return _isInitializing();
+    }
+
+    function initialize() public initializer {
+        initializerRan = true;
+    }
+
+    function initializeOnlyInitializing() public onlyInitializing {
+        onlyInitializingRan = true;
+    }
+
+    function initializerNested() public initializer {
+        initialize();
+    }
+
+    function onlyInitializingNested() public initializer {
+        initializeOnlyInitializing();
+    }
+
+    function initializeWithX(uint256 _x) public payable initializer {
+        x = _x;
+    }
+
+    function nonInitializable(uint256 _x) public payable {
+        x = _x;
+    }
+
+    function fail() public pure {
+        require(false, "InitializableMock forced failure");
+    }
+}
+
+contract ConstructorInitializableMock is Initializable {
+    bool public initializerRan;
+    bool public onlyInitializingRan;
+
+    constructor() initializer {
+        initialize();
+        initializeOnlyInitializing();
+    }
+
+    function initialize() public initializer {
+        initializerRan = true;
+    }
+
+    function initializeOnlyInitializing() public onlyInitializing {
+        onlyInitializingRan = true;
+    }
+}
+
+contract ChildConstructorInitializableMock is ConstructorInitializableMock {
+    bool public childInitializerRan;
+
+    constructor() initializer {
+        childInitialize();
+    }
+
+    function childInitialize() public initializer {
+        childInitializerRan = true;
+    }
+}
+
+contract ReinitializerMock is Initializable {
+    uint256 public counter;
+
+    function getInitializedVersion() public view returns (uint8) {
+        return _getInitializedVersion();
+    }
+
+    function initialize() public initializer {
+        doStuff();
+    }
+
+    function reinitialize(uint8 i) public reinitializer(i) {
+        doStuff();
+    }
+
+    function nestedReinitialize(uint8 i, uint8 j) public reinitializer(i) {
+        reinitialize(j);
+    }
+
+    function chainReinitialize(uint8 i, uint8 j) public {
+        reinitialize(i);
+        reinitialize(j);
+    }
+
+    function disableInitializers() public {
+        _disableInitializers();
+    }
+
+    function doStuff() public onlyInitializing {
+        counter++;
+    }
+}
+
+contract DisableNew is Initializable {
+    constructor() {
+        _disableInitializers();
+    }
+}
+
+contract DisableOld is Initializable {
+    constructor() initializer {}
+}
+
+contract DisableBad1 is DisableNew, DisableOld {}
+
+contract DisableBad2 is Initializable {
+    constructor() initializer {
+        _disableInitializers();
+    }
+}
+
+contract DisableOk is DisableOld, DisableNew {}