Liquibase-slf4j Updated to support Liquibase 4.x

Hi. I’m the maintainer of the liquibase-slf4j library. I’ve updated it to support the recent release of Liquibase 4.0. The jar is in Maven Central now. Just an FYI for those who stumble upon this in their search. Please report any issues to the link below.

Thanks @MattBertolini!