Default crate version should be highest version, not most recent released

[shssoichiro]

For example: iron-0.3.1 was released more recently than iron-0.4.0. Therefore, the default version linked to on docs.rs is 0.3.1, when the highest version is actually 0.4.0. It would make more sense to default to the highest version number.

[onur]

I believe this issue is fixed since docs.rs started using semver for matching versions. It is now returning greatest version instead of most recent one.