Merge pull request #1334 from jhlegarreta/FixNumpyCoreRenamed

RF: Use `numpy.lib.scimath` to demonstrate warning context manager

nibabel/testing/__init__.py

@@ -150,9 +150,10 @@ class clear_and_catch_warnings(warnings.catch_warnings):
     Examples
     --------
     >>> import warnings
-    >>> with clear_and_catch_warnings(modules=[np.core.fromnumeric]):
+    >>> with clear_and_catch_warnings(modules=[np.lib.scimath]):
     ...     warnings.simplefilter('always')
-    ...     # do something that raises a warning in np.core.fromnumeric
+    ...     # do something that raises a warning in np.lib.scimath
+    ...     _ = np.arccos(90)
     """
 
     class_modules = ()