Remove Slack notification from Provision stage
Remove Slack notification from Provision stage

This was creating a lot of unwanted noise

chef/omnitruck,chef/opscode-omnitruck,chef/opscode-omnitruck,juliandunn/opscode-omnitruck,juliandunn/opscode-omnitruck,chef/omnitruck,chef/opscode-omnitruck,chef/omnitruck,juliandunn/opscode-omnitruck