Write programs which would accomplish the following program descriptions.
      Write a Python function remove_blue(a_picture),
      which sets the blue component of each pixel to 0 in the image.
      It should leave the red and green component of each pixel alone.
    
      Write a Python function swap_red_blue(a_picture),
      which swaps the values for the red and blue components of each
      pixel.  It should leave green component of each pixel alone.