Update dependencies for Scala 2.12

[davidmweber]

-The dependency for scala-logging-slf4j has no 2.12 version in Maven Central. Perhaps some other logger is appropriate

• There are a bunch of deprecations under 2.12

[julianpeeters]

Hi @davidmweber, thanks for the attention to this issue.

I'm open to any other logger if you have a suggestion, else removing the logger (some people like it, but it never worked right, and support for Scala 2.12 seems like a higher priority).

The deprecations don't concern me much yet: I was hoping to move everything over to scala.meta this summer, and if that plan changes, the deprecations can be addressed then.

[davidmweber]

Morning!
Agree re deprecations. Logger are something that this library should leave to whoever uses it. As the tests pass without it, I would just ignore it for now or rip it out. Builds and tests fine without the dependency and it seems you have a path where logging becomes moot.