please add support for pathlib in pyFAI

[picca]

Hello, when using pathlib instead of a str in pyFAI.load, I get this error message.

It would be nice to support out of the box pathlib :)

PONI = PUBLISHED / "scan_0567_0002_0.poni"

ai = pyFAI.load(PONI)

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-15-49f83512f163> in <module>()
      1 PONI = PUBLISHED / "scan_0567_0002_0.poni"
      2 
----> 3 ai = pyFAI.load(PONI)
      4 
      5 fns = [ROOT /  "scan_{:04d}_01.nxs".format(i) for i in range(567)]

/usr/lib/python3/dist-packages/pyFAI/__init__.py in load(filename)
     83     """
     84     from .azimuthalIntegrator import AzimuthalIntegrator
---> 85     return AzimuthalIntegrator.sload(filename)
     86 
     87 

/usr/lib/python3/dist-packages/pyFAI/geometry.py in sload(cls, filename)
   1192         """
   1193         inst = cls()
-> 1194         inst.load(filename)
   1195         return inst
   1196 

/usr/lib/python3/dist-packages/pyFAI/geometry.py in load(self, filename)
   1203         :return: itself with updated parameters
   1204         """
-> 1205         poni = ponifile.PoniFile(data=filename)
   1206         self._init_from_poni(poni)
   1207         return self

/usr/lib/python3/dist-packages/pyFAI/io/ponifile.py in __init__(self, data)
     67             self.read_from_file(data)
     68         else:
---> 69             self.read_from_duck(data)
     70 
     71     def read_from_file(self, filename):

/usr/lib/python3/dist-packages/pyFAI/io/ponifile.py in read_from_duck(self, duck)
    147         """
    148         # TODO: It would be good to test attribute types
--> 149         self._dist = duck.dist
    150         self._poni1 = duck.poni1
    151         self._poni2 = duck.poni2

AttributeError: 'PurePosixPath' object has no attribute 'dist'

[kif]

quite straight forwards ... PR welcome

[picca]

In that case can you add a tag showing that this is trivial.

then I will ask my apprentice to look after these trivial changes.

thanks

Fred