update specs

Author: oesteban

nipype/interfaces/ants/tests/test_auto_AffineInitializer.py

@@ -28,6 +28,9 @@ def test_AffineInitializer_inputs():
     mandatory=True,
     position=2,
     ),
+    num_threads=dict(nohash=True,
+    usedefault=True,
+    ),
     out_file=dict(argstr='%s',
     position=3,
     usedefault=True,