restore git as ola asked for it

src/git/tests/test_server.py

@@ -0,0 +1,30 @@
+import pytest
+from pathlib import Path
+import git
+from mcp_server_git.server import git_checkout
+import shutil
+
+@pytest.fixture
+def test_repository(tmp_path: Path):
+    repo_path = tmp_path / "temp_test_repo"
+    test_repo = git.Repo.init(repo_path)
+
+    Path(repo_path / "test.txt").write_text("test")
+    test_repo.index.add(["test.txt"])
+    test_repo.index.commit("initial commit")
+
+    yield test_repo
+
+    shutil.rmtree(repo_path)
+
+def test_git_checkout_existing_branch(test_repository):
+    test_repository.git.branch("test-branch")
+    result = git_checkout(test_repository, "test-branch")
+
+    assert "Switched to branch 'test-branch'" in result
+    assert test_repository.active_branch.name == "test-branch"
+
+def test_git_checkout_nonexistent_branch(test_repository):
+
+    with pytest.raises(git.GitCommandError):
+        git_checkout(test_repository, "nonexistent-branch")