rflex 0.4.0

## 0.4.0 (2019-06-19)

* Remove unsafe `std::mem::transmute` call by @au-phiware ([#5](https://github.com/pfnet/rflex/pull/5))
  * This changes Lexer interface that replaced `String` with `&str`


## 0.3.0 (2019-05-24)

* Support multi-line action code block


## 0.2.0 (2019-04-11)

* Public `rflex::process` function


## 0.1.0 (2019-04-08)

* Initial release