Implement a command to upgrade salt-minion on HNs (OMS-298)
Implement a command to install Salt on all machines (OMS-298)
Let metrics requests timeout + additional logging (OMS-267)
Safe outstanding request deletion (OMS-267)
Merge pull request #47 from opennode/oms-267

Let metrics requests timeout if stuck (OMS-267)
Merge branch 'oms-298'

Conflicts:
	opennode/knot/backend/salt/__init__.py
Additional safe deletion fix (OMS-267)