Importing deleted dipy function `affine_from_fsl_mat_file`

[koenhelwegen]

The function affine_from_fsl_mat_file is imported and used here:

nipype/nipype/interfaces/mrtrix/convert.py

Line 196 in f756b71

from dipy.tracking.utils import move_streamlines, affine_from_fsl_mat_file

However, this function was deleted in dipy/dipy@a700df9#diff-24e3afc30f00cdbf9015dffb73ce1d2ab08ae582ebdc519b218361b5ff904e7e

I'm not sure what happened to the functionality in dipy, I will try to look into this more later.