logging

Two things worth noting:
  1. `MaestroCascade.validate` function throws exception if jobs have the same name. This is technically backwards incompatible. I am happy to take this code out if necesary. Either way I will get rid of the TODO comment before pushing to master.
  2. I don`t want to add anything to `maestro-example` until the omnitool logger functions ready for use in maestro.
Yeah, but if there are any jobs out there that do not have unique names, than when they upgrade maestro, they will be forced to make the names unique. Which is probably not the worst thing to happen, but I wanted to get other people's opinion.