add missing edit in mrtrix3

Author: oesteban

nipype/interfaces/mrtrix3/__init__.py

@@ -2,5 +2,6 @@
 # vi: set ft=python sts=4 ts=4 sw=4 et:
 # -*- coding: utf-8 -*-
 
+from utils import Mesh2PVE
 from preprocess import ResponseSD
 from tracking import Tractography