ByteStride is missing from BufferView output

[schubboy]

Looks like the ByteStride attribute was never finished for the bufferview output (line 1155), or was for some reason commented out? I cannot find where the stride is computed or recorded, so I guess this is still a todo. But this library, as nice as it is, will not work without the bytestride being output.

Technically i guess you don't need stride if you're creating a separate buffer view for each accessor type, but I don't see that happening either...looks like its just incomplete implementation of the GLTF spec...