Merge pull request #1715 from njsmith/deflake-test_pipes

Bump up the timeout in test_pipes to hopefully reduce spurious CI failures

Author: altendky

trio/tests/test_subprocess.py

@@ -134,8 +134,8 @@ async def check_output(stream, expected):
             assert seen == expected
 
         async with _core.open_nursery() as nursery:
-            # fail quickly if something is broken
-            nursery.cancel_scope.deadline = _core.current_time() + 3.0
+            # fail eventually if something is broken
+            nursery.cancel_scope.deadline = _core.current_time() + 30.0
             nursery.start_soon(feed_input)
             nursery.start_soon(check_output, proc.stdout, msg)
             nursery.start_soon(check_output, proc.stderr, msg[::-1])