fix unittest

Author: koxudaxi

tests/data/expected/openapi/custom_template_security/custom_security/models.py

@@ -2,6 +2,8 @@
 #   filename:  custom_security.yaml
 #   timestamp: 2020-06-19T00:00:00+00:00
 
+from __future__ import annotations
+
 from typing import Optional
 
 from pydantic import BaseModel

tests/data/expected/openapi/default_template/body_and_parameters/models.py

@@ -2,6 +2,8 @@
 #   filename:  body_and_parameters.yaml
 #   timestamp: 2020-06-19T00:00:00+00:00
 
+from __future__ import annotations
+
 from typing import Optional
 
 from pydantic import BaseModel

tests/data/expected/openapi/default_template/oas_response_reference/models.py

@@ -2,6 +2,8 @@
 #   filename:  oas_response_reference.yaml
 #   timestamp: 2020-06-19T00:00:00+00:00
 
+from __future__ import annotations
+
 from typing import Optional
 
 from pydantic import BaseModel

tests/data/expected/openapi/default_template/simple/models.py

@@ -2,6 +2,8 @@
 #   filename:  simple.yaml
 #   timestamp: 2020-06-19T00:00:00+00:00
 
+from __future__ import annotations
+
 from typing import List, Optional
 
 from pydantic import BaseModel, Field

tests/data/expected/openapi/remote_ref/body_and_parameters/models.py

@@ -2,6 +2,8 @@
 #   filename:  body_and_parameters.yaml
 #   timestamp: 2020-06-19T00:00:00+00:00
 
+from __future__ import annotations
+
 from typing import Optional
 
 from pydantic import BaseModel