Features
- Adds `Maybe` container
- Adds immutability and `__slots__` to all containers
- Adds methods to work with failures
- Adds `safe` decorator to convert exceptions to `Result` container
- Adds `is_successful()` function to detect if your result is a success
- Adds `failure()` method to unwrap values from failed containers
Bugfixes
- Changes the type of `.bind` method for `Success` container
- Changes how equality works, so now `Failure(1) != Success(1)`
- Changes how new instances created on unused methods
Misc
- Improves docs