Why is `Distance` not an analyzer? 

The [Distance](https://github.com/awslabs/deequ/blob/9601dc3a7147dc8f91e0e4c70e74d8c1570a20ec/src/main/scala/com/amazon/deequ/analyzers/Distance.scala#L26) object seems to provide useful utilties to detect drift. But why does it not implement the `Analyzer` trait like other utilities in that package?

Due to this it seems we can not use this with `AnalysisRunner`. Is there a reason for this?
