Merge pull request #193 from dnephin/0.5.2_state_migration_tools

State migration tools
Add warning to working_dir() context manager.
Merge branch 'release_0.5.2' of github.com:Yelp/Tron into 0.5.2_state_watcher_for_reconfigure
Merge branch 'release_0.5.2' of github.com:Yelp/Tron into 195_scheduling_after_reconfigure
Merge pull request #194 from dnephin/0.5.2_state_watcher_for_reconfigure

0.5.2 state watcher for reconfigure
Merge pull request #196 from dnephin/195_scheduling_after_reconfigure

195 scheduling after reconfigure
Merge branch 'release_0.5.2' of github.com:Yelp/Tron into r0.6_service_refactor
Remove ZAP, and fix service instance transitions.