Give the test more time to shut down (#115)

CI has been seeing some flakes with the 1 second timeout.

Author: jwnimmer-tri

test/server_test.py

@@ -69,7 +69,7 @@ def setUp(self, extra_server_args=None):
 
     def tearDown(self):
         self.server_proc.terminate()
-        self.assertEqual(self.server_proc.wait(1.0), -signal.SIGTERM)
+        self.assertEqual(self.server_proc.wait(10.0), -signal.SIGTERM)
 
     def _render_and_check(
         self,