Error in new NiBabelModelIO

[phcerdan]

No volume information contained in the file
Traceback (most recent call last):
  File "/path/Software/Slicer/Slicer-5.6.1-linux-amd64/slicer.org/Extensions-32438/SlicerFreeSurfer/lib/Slicer-5.6/qt-scripted-modules/NiBabelModelIO.py", line 169, in readModelNode
    geom = VolGeom.from_surf_footer(metadata)
  File "/path/Software/Slicer/Slicer-5.6.1-linux-amd64/slicer.org/Extensions-32438/SlicerFreeSurfer/lib/Slicer-5.6/qt-scripted-modules/NiBabelModelIO.py", line 70, in from_surf_footer
    shape=footer['volume'],
KeyError: 'volume'
[Qt] "/path/Software/Slicer/Slicer-5.6.1-linux-amd64/slicer.org/Extensions-32438/SlicerFreeSurfer/lib/Slicer-5.6/qt-scripted-modules/NiBabelModelIO.py"  - In "NiBabelModelIOFileReader" class, function 'write'  is expected to return a string boolean !
[Qt] static void qSlicerIOManager::showLoadNodesResultDialog(bool, vtkMRMLMessageCollection*) Errors occurred while loading nodes: "Error: Loading /tmp/lh-filled-outer-surface.pial - Could not load file: /tmp/lh-filled-outer-surface.pial\n"

lh-filled-outer-surface.zip

The file was saved using MRISwrite function in a custom mris. Freeview is able to load the file.
This must be related to changes introduced to solve #17