FIX fix split_filename behaviour when path has no filename

Author: Mathieu Dubois

nipype/utils/filemanip.py

@@ -61,10 +61,8 @@ def split_filename(fname):
 
     special_extensions = [".nii.gz", ".tar.gz"]
 
-    if fname and fname.endswith(os.path.sep):
-        fname = fname[:-1]
-
-    pth, fname = os.path.split(fname)
+    pth = os.path.dirname(fname)
+    fname = os.path.basename(fname)
 
     ext = None
     for special_ext in special_extensions: