Replace try { ... } catch { case t: Throwable => ... } with scala.util.Try

Catching Throwable is a generally bad idea that can leave your JVM in a
useless (undead) state. Try is more reasonable, and catches non-fatal
exceptions only (see scala.util.control.NonFatal for details).

Also removed a match on JsonMappingException because it is a subclass of
JsonProcessingException (already caught).
Merge pull request #205 from gilt/remove_catch_throwable

Replace try { ... } catch { case t: Throwable => ... } with scala.util.Try