Added new commands for HAProxy and Canary

• Adds a new helper for chef, currently supports getting names and ips from roles
• Adds a new helper for haproxy that can be used from chatops commands, currently supports a query for server status and set server states
• Adds a new canary command, by default the command will query status. Optionally you can set the state of a given backend (or all backends if not specified)

Controls canary traffic

Usage: canary [OPTIONS]

Options:

  -h, --help    Shows this help message
  --production  Control production canary traffic instead of staging
  --ready       Set canary to enable connections
  --drain       Set canary to drain connections
  --maint       Set canary to be disabled
  --backend     Filter by a specific backend