diff(1) not found in CoreOS

[mirakui]

With CoreOS stable (607.0.0) and Itamae v1.2.12, applying remote_file resource causes following error message because CoreOS doesn't have diff(1).

> itamae ssh -h coreos-01 roles/aws/coreos/default.rb
 INFO : Starting Itamae...
 INFO : Recipe: /Users/mirakui/src/itamae_recipes/roles/aws/coreos/default.rb
 INFO :   diff:
 INFO :   /bin/sh: diff: command not found

recipe:

remote_file '/usr/share/oem/cloud-config.yml' do
  owner 'root'
  group 'root'
  mode '0644'
  source 'files/cloud-config.yml'
end

but the applying succeeded.

[ryotarai]

I see...
As you know, currently, Itamae generates diff by diff command on the target host. I'll change it to do that on the host Itamae is running.