Add unit test for testing adding a gent

tests/unit/test_commands.py

@@ -0,0 +1,13 @@
+from autogpt import commands
+import unittest
+from unittest.mock import patch,MagicMock
+
+class TestCommands(unittest.TestCase):
+    def test_make_agent(self):
+        with patch("openai.ChatCompletion.create") as mock:
+            obj = MagicMock()
+            obj.response.choices[0].messages[0].content = "Test message"
+            mock.return_value = obj
+            commands.start_agent("Test Agent", "chat", "Hello, how are you?", "gpt2")
+            agents = commands.list_agents()
+            self.assertEqual(agents[0], (0,'chat'))