[MAINT] Import only Sequence to avoid DeprecationWarning

Author: oesteban

nipype/interfaces/base/traits_extension.py

@@ -25,7 +25,7 @@
 
 from builtins import str, bytes
 import os
-import collections
+from collections import Sequence
 
 # perform all external trait imports here
 from traits import __version__ as traits_version
@@ -323,7 +323,7 @@ def validate(self, object, name, value):
 
         # want to treat range and other sequences (except str) as list
         if not isinstance(value, (str, bytes)) and isinstance(
-                value, collections.Sequence):
+                value, Sequence):
             value = list(value)
 
         if not isdefined(value) or \