message: Update convolutional.py
  Updating `stride` argument in `SeparableConv2D` class as it currently supports  equal
  length strides in the row and column dimensions.
  Fixes the issue
diff: @@ -2106,7 +2106,8 @@ class SeparableConv2D(SeparableConv):
  strides: An integer or tuple/list of 2 integers,
  specifying the strides of the convolution along the height and width.
  Can be a single integer to specify the same value for
  - all spatial dimensions.
  + all spatial dimensions. Current implementation only supports equal
  + length strides in the row and column dimensions.
  Specifying any stride value != 1 is incompatible with specifying
  any `dilation_rate` value != 1.
  padding: one of `"valid"` or `"same"` (case-insensitive).
  