MAINT: Rearrange files in numpy/testing module.

The aim here is to separate out the nose dependent files prior to adding
pytest support. This could be done by adding new files to the general
numpy/testing directory, but I felt that it was to have the relevant
files separated out as it makes it easier to completely remove nose
dependencies when needed.

Many places were accessing submodules in numpy/testing directly, and in
some cases incorrectly. That presented a backwards compatibility
problem. The solution adapted here is to have "dummy" files whose
contents will depend on whether of not pytest is active. That way the
module looks the same as before from the outside.

In the case of numpy itself, direct accesses have been fixed. Having
proper `__all__` lists in the submodules helped in that.

1 files changed, 2 insertions, 4 deletions

diff --git a/numpy/tests/test_warnings.py b/numpy/tests/test_warnings.py
index c5818d21c..7f22794ec 100644
--- a/numpy/tests/test_warnings.py
+++ b/numpy/tests/test_warnings.py
@@ -13,9 +13,7 @@ if sys.version_info >= (3, 4):
     import ast
     import tokenize
     import numpy
-    from numpy.testing import run_module_suite
-    from numpy.testing.decorators import slow
-
+    from numpy.testing import run_module_suite, dec
 
     class ParseCall(ast.NodeVisitor):
         def __init__(self):
@@ -63,7 +61,7 @@ if sys.version_info >= (3, 4):
                     "{} on line {}".format(self.__filename, node.lineno))
 
 
-    @slow
+    @dec.slow
     def test_warning_calls():
         # combined "ignore" and stacklevel error
         base = Path(numpy.__file__).parent