Allow for easier version compatibility checking.

[iddm]

By deriving Ord and PartialOrd we can compare two versions easier. We need to be able to compare the versions to make sure the compatible version is used with the module.

[iddm]

An example:

fn main() {
    #[derive(Debug, PartialEq, Eq, Ord, PartialOrd)]
    pub struct Version {
        pub major: i32,
        pub minor: i32,
        pub patch: i32,
    }
    
    let redis = Version {
        major: 6,
        minor: 0,
        patch: 3,
    };
    let gears = Version {
        major: 7,
        minor: 0,
        patch: 3,
    };
    
    println!("Result: {:?}", redis.cmp(&gears));
}