Merge pull request #1 from HubSpot/master

Merge from hubspot
Merge pull request #2 from HubSpot/master

Merge from hubspot
Merge pull request #3 from HubSpot/master

Merge from Hubspot
Get active/dead/decomissioning racks with Singularity client
Decomission / delete slave
decomission / delete racks
Merge pull request #4 from HubSpot/master

Merge from Hubspot
Merge pull request #5 from HubSpot/master

Merge from Hubspot
Merge pull request #213 from jloisel/master

Feature: support list / decomission / delete of racks / slaves in Singularity client