Increase Erchef Ticket TTL

chef-client runs may die on long running steps with a 403 error. This is
because the auth ticket has expired. Increasing the timeout so this
happens much less frequently, esp. given our complex setups.

See: https://tickets.opscode.com/browse/CHEF-3045
Make quoting more consistent in chef-server.rb
Merge pull request #16 from claco/erchef-ttl-timouts

Increase Erchef Ticket TTL