Add exception handling to scald.rb

This will allow the scald.rb script to accept --help parameter (and give help as a result)
Merge pull request #326 from willf/develop

Add exception handling to scald.rb
Add sample method to RichPipe
Add return types to limit and sample
Merge pull request #327 from willf/develop

Add sample method to RichPipe
Update scripts/scald.rb

Update for the refactored away build.sbt as well as accommodate
the new sbt version format in version.sbt. Fixes #325
Merge pull request #331 from rickeyvisinski-kanban/patch-1

Update scripts/scald.rb