fix: pconfig shouldn't import from snakeoil tests

Snakeoil had this class moved out, update pconfig accordingly.

Signed-off-by: Brian Harring <ferringb@gmail.com>

Author: ferringb

src/pkgcore/scripts/pconfig.py

@@ -5,7 +5,7 @@
 from functools import partial
 
 from snakeoil.errors import dump_error
-from snakeoil.test.mixins import PythonNamespaceWalker
+from snakeoil.python_namespaces import PythonNamespaceWalker
 
 from ..config import basics, errors
 from ..ebuild import atom