Tighten test to ensure coverage

Reducing the number of possible elements ensures that the unique-with-explicit-fill code is fully excercised.

hypothesis-python/tests/numpy/test_gen_data.py

@@ -25,7 +25,7 @@
 
 import hypothesis.strategies as st
 import hypothesis.extra.numpy as nps
-from hypothesis import given, assume, settings
+from hypothesis import HealthCheck, given, assume, settings
 from hypothesis.errors import InvalidArgument
 from tests.common.debug import minimal, find_any
 from tests.common.utils import checks_deprecated_behaviour
@@ -240,8 +240,9 @@ def test_may_fill_with_nan_when_unique_is_set():
 
 
 def test_is_still_unique_with_nan_fill():
+    @settings(suppress_health_check=HealthCheck.all())
     @given(nps.arrays(
-           dtype=float, elements=st.floats(allow_nan=False), shape=10,
+           dtype=float, elements=st.integers(0, 9), shape=10,
            unique=True, fill=st.just(float('nan'))))
     def test(xs):
         assert len(set(xs)) == len(xs)