Attempting to use the crate with a no_std target, such as wasm32v1-none is currently not supported due to:

• the lack of #![no_std] within lib.rs
• the inclusion of default features on dependencies such as serde
• the unconditional use of std::time::SystemTime, even though it's only required for functions related to current time

Experimenting, this crate can be no_std compatible through the addition of an std feature to conditionally compile SystemTime related APIs, and disabling default features on dependencies (that's worth doing anyway since it improves compile times).

I'm currently working on a PR to implement these changes.