"Implement" resizing images to non-2d shapes
"Implement" resizing images to non-2d shapes

Part of removing todos. Implemented by removing assertion against the
contrary.

mindriot101/rust-fitsio,mindriot101/rust-fitsio,mindriot101/rust-cfitsio,mindriot101/rust-fitsio,mindriot101/rust-fitsio,mindriot101/rust-fitsio,mindriot101/rust-cfitsio