Integrate asher-stern/CRF

[Horsmann]

Should be inspected first if suited for an integration

https://github.com/asher-stern/CRF

<dependency>
    <groupId>com.github.asher-stern</groupId>
    <artifactId>CRF</artifactId>
    <version>1.2.0</version>
</dependency>

MIT license