Fix quantumlib#1062: ignore warning from a Cirq function about Qiskit (quantumlib#1063)

The code in `src/openfermion/testing/wrapped.py` calls
`cirq.testing.assert_implements_consistent_protocols`. The latter
funtion prints warnings about the Cirq function
`assert_qasm_is_consistent_with_unitary` when Qiskit is not installed.
This is irrelevant to testing OpenFermion; it doesn't do anything with
QASM and we certainly don't want to introduce a dependency on Qiskit.

Resolves issue quantumlib#1062.

Author: mhucka

dev_tools/conf/pytest.ini

@@ -18,3 +18,6 @@ markers =
 
 # Silence deprecation warnings about option "asyncio_default_fixture_loop_scope"
 asyncio_default_fixture_loop_scope = "function"
+
+filterwarnings =
+    ignore:Skipped assert_qasm_is_consistent_with_unitary because qiskit.*:UserWarning