Release 0.3.0

# Release 0.3.0

## Breaking changes

* `or_else` is renamed to `get_or_else`. This change unifies the API naming. All the methods that start with `get_` return the unwrapped value. **Migration:** Go through your project and replace all `or_else` methods calls to `get_or_else`

## Additions

* The new `or_else` method: Returns the current `Maybe` if it's `Some`, otherwise it returns what is given as a parameter.
* `combine`: Takes two `Maybe`s and returns a new `Maybe` which contains and array of the values of the two combined `Maybe`s.
* `inner`: Forwards the method call straight to the value
* `lazy`: `Maybe` can be used lazily. You can call `lazy` to any `Maybe` and get back a lazy version. Also, you can initialize a new `Maybe` lazily by giving it a block.