Remove keep-alive header from responses. First of all, it should say timeout=<value> which wasn't the case with existing implementation, and secondly none of the other web servers I tried include this header.

tests/test_response.py

@@ -82,7 +82,6 @@ def test_response_header(app):
     request, response = app.test_client.get("/")
     assert dict(response.headers) == {
         "connection": "keep-alive",
-        "keep-alive": str(app.config.KEEP_ALIVE_TIMEOUT),
         "content-length": "11",
         "content-type": "application/json",
     }