RF - remove deprecated save class method

Author: matthew-brett

nibabel/spatialimages.py

@@ -506,14 +506,6 @@ def make_file_map(klass, mapping=None):
     def load(klass, filename):
         return klass.from_filename(filename)
 
-    @classmethod
-    def save(klass, img, filename):
-        warnings.warn('``save`` class method is deprecated\n'
-                      'You probably want the ``to_filename`` instance '
-                      'method, or the module-level ``save`` function',
-                      DeprecationWarning, stacklevel=2)
-        klass.instance_to_filename(img, filename)
-
     @classmethod
     def instance_to_filename(klass, img, filename):
         ''' Save `img` in our own format, to name implied by `filename`