Parlour integration

Not yet for commit.

This how I anticipate the integration working, I'm just not sure the best way to make sure the sqoop job is used as a dependency yet.

I can pass in a tap/source to the Import/ExportSqoopJob, but I'm not entirely sure how scalding will match it up with what gets used in the load.

hm.
There is now a `Clean.default` cleaner that does this. We should start using it in most cases.