test: Update version in test_user_agent

Author: skupriienko

test.py

@@ -215,7 +215,7 @@ def test_user_agent(self) -> None:
         None
         """
         self.client = Client(auth=self.auth, version="v3.1")
-        self.assertEqual(self.client.config.user_agent, "mailjet-apiv3-python/v1.4.0")
+        self.assertEqual(self.client.config.user_agent, "mailjet-apiv3-python/v1.5.0")
 
 
 class TestCsvImport(unittest.TestCase):