Beginning garbage collector for marked containers
mark and remove stale containers with exit or no status
force a container to be removed
Adjusted interval to MS, fixed indent, and filtering for stale containers
Better handling of marking stale containers
(WIP) event emit
GC should emit events
Updated libraries that remove containers
Made tests more sane by using wait_for_event
Merge pull request #39 from gregarndt/garbage_collection

Garbage collection
Garbage Collection - Free image space
Pull from default config for gc settings
Images will be removed when expiration is reached
Updated package dependencies for diskspace
Fixed tests, added comments, and remove all images if threshold is met
Fixed poor use of passthrough stream.  Pipe everything to stdout now.
use worker config for docker volume and improve logging
Pull image with 'latest' tag if no tag specified
Remove duplicate code for parsing image name
Fixed up some formatting and added some useful comments