fix #65, wrong version numbering scheme.
fix #65, wrong version numbering scheme.

Cobrand/rust-sdl2,Rust-SDL2/rust-sdl2,vadixidav/rust-sdl2,Cobrand/rust-sdl2,AngryLawyer/rust-sdl2,xsleonard/rust-sdl2_image,crumblingstatue/rust-sdl2_image,Rust-SDL2/rust-sdl2,Cobrand/rust-sdl2,Rust-SDL2/rust-sdl2