maint: fix numpy float construction

numpy.float was deprecated as it was just python's float. using
np.float64 explicitly

Author: wagner-intevation

tests/test_output_format.py

@@ -366,7 +366,7 @@ def test_json_converter_numpy_types():
     ex_int = numpy.int_(9)
     ex_np_array = numpy.array([1, 2, 3, 4, 5])
     ex_np_int_array = numpy.int_([5, 4, 3])
-    ex_np_float = numpy.float(0.5)
+    ex_np_float = numpy.float64(0.5)
 
     assert 9 == hug.output_format._json_converter(ex_int)
     assert [1, 2, 3, 4, 5] == hug.output_format._json_converter(ex_np_array)