Small bug in Bars and Stripes dataset

[Ilmosal]

Hi!

There is an indexing bug in the module for creating the bars and stripes dataset. If the height and width are not the same size, the script throws an out-of-bounds exception, as the height and width seem to be mixed up in the code. I fixed it for myself locally by just swapping the height and width when creating the base numpy array for the dataset.

[josephbowles]

Hi! thanks for pointing that out. I'll push a correction now.