fix: Send Vary: Accept-Encoding on any data that could be compressed This allows upstream caches to return the correct data even when compression is not in use. It is not sent if the content would never be compressed. I.E. size < 100 bytes, dynamic compression disabled, file would not benefit from compression (img/jpeg, img/png). Fix setVary to add header to vary list only if it's not already there. Found by redbot.org testing. References: https://www.stackpath.com/blog/accept-encoding-vary-important/

# simple way to see if there are order dependencies in tests
# can use if pytest-random-order --random-order mode isn't
# usable (e.g. python2).

#def pytest_collection_modifyitems(items): 
#    items.reverse()

# Add a marker for pg_schema tests.
# They duplicate the postgresql tests exactly but uses a named
# schema rather than the default 'public' schema.
def pytest_configure(config):
    config.addinivalue_line(
        "markers", "pg_schema: tests using schema for postgres"
    )