Updated dependencies

[nadenf]

No description provided.

[johannesvollmer]

Hi! Thanks for taking the time to contribute. However, it's better for users if we keep the versions at the lowest possible - it allows cargo to merge the dependencies with other dependencies in their project. Cargo will automatically use the newest version of each crate, because we only specify the minimum version using ^.

The reason that half is limited even more is to stay compatible with the older rust compilers.

Still I appreciate your efforts and good intentions :)