Duplicate resource conflict when cobbler enabled on AIO

When cobbler is enabled in the AIO scenario, there is a potential duplicate resource conflict when defining hosts in the /etc/hosts file.

https://github.com/CiscoSystems/puppet-coi/blob/icehouse/manifests/profiles/cobbler_server.pp#L253-L257

https://github.com/CiscoSystems/puppet-coe/blob/icehouse/manifests/base.pp#L251-L257

Both are wrapped in an ensure_resource, but this can still cause a duplicate resource error if the information defined in each instance doesn't match. Because install.sh creates a user.yaml file for the AIO case and adds the controller addresses in it but doesn't add a cobbler_node_ip entry, the address info in the two resources can be different. To fix, we should have install.sh add a cobbler_node_ip entry to user.yaml.