add：

1.moderation tools
2.unittest

tests/metagpt/tools/test_moderation.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+@Time    : 2023/9/26 14:46
+@Author  : zhanglei
+@File    : test_translate.py
+"""
+
+import pytest
+
+from metagpt.tools.moderation import Moderation
+
+
+@pytest.mark.parametrize(
+    ("content",),
+    [
+        [
+            ["I will kill you", "The weather is really nice today", "I want to hit you"],
+        ]
+    ],
+)
+def test_moderation(content):
+    moderation = Moderation()
+    results = moderation.moderation(content=content)
+    assert isinstance(results, list)
+    assert len(results) == len(content)
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    ("content",),
+    [
+        [
+            ["I will kill you", "The weather is really nice today", "I want to hit you"],
+        ]
+    ],
+)
+async def test_amoderation(content):
+    moderation = Moderation()
+    results = await moderation.amoderation(content=content)
+    assert isinstance(results, list)
+    assert len(results) == len(content)