integrate reviews from ChristophRaab:master

prototorch/modules/models.py

@@ -1,12 +1,9 @@
 import torch
-from prototorch.functions.distances import (euclidean_distance_matrix,
-                                            tangent_distance)
-from prototorch.functions.helper import _check_shapes, _int_and_mixed_shape
+from prototorch.functions.distances import euclidean_distance_matrix
 from prototorch.functions.normalization import orthogonalization
 from prototorch.modules.prototypes import Prototypes1D
 from torch import nn
 
-
 class GTLVQ(nn.Module):
     r""" Generalized Tangent Learning Vector Quantization