add a test for q_lvl

tests/test_probabilist.py

@@ -163,7 +163,7 @@ class TestMetrics(unittest.TestCase):
     def test_intervals_qlvl_metrics(self):
         lvl = numpy.array([50., 80.])
         qlvl = numpy.array([10., 25., 75., 90])
-        for metric in expected_itv_qlvl.keys():
+        for metric in self.expected_itv_qlvl.keys():
 
             numpy.set_printoptions(precision=13)
             m = evalhyd.evalp(_obs, _prd, [metric], c_lvl=lvl, q_lvl=qlvl)[0][0, 0, 0]