If using exponential back-off, let's use 10sec delay

Author: mhucka

src/openfermion/chem/pubchem_test.py

@@ -149,7 +149,7 @@ def test_water_2d(self, monkeypatch):
         with pytest.raises(ValueError, match='Incorrect value for the argument structure'):
             _ = geometry_from_pubchem('water', structure='foo')
 
-    @pytest.mark.flaky(retries=3, delay=5, backoff=2, only_on=[pubchempy.ServerBusyError])
+    @pytest.mark.flaky(retries=3, delay=10, backoff=2, only_on=[pubchempy.ServerBusyError])
     def test_geometry_from_pubchem_live_api(self):
         water_geometry = geometry_from_pubchem('water')
         assert len(water_geometry) == 3