crab 0.2.0

Provides Rust-like Result and Option type.

0.2.0

• Added Result methods. You can use almost all the features of Rust's Result trait (exclude nightly-only features).
• Fixed Ok#toString, Err#toString, Some#toString, and None#toString.
• Breaking: Result#flatMep is removed. You can use Result#andThen instead.
• Breaking: Changed Ok.value and Err.err to private. You can use Result#unwrap and Result#unwrapErr instead.
• Breaking: Changed Some.value to private. You can use Option#unwrap instead.

0.1.0

• Initial release