Copy the app and ossec alert gpg key to remote host

Added task to copy the app and ossec alert gpg keys to the respective remote hosts since Vagrant will not be used in production and mount.

Removed the word 'path' from the the variable names for the app/ossec gpg key and the custom header image variables since it does not a path anymore.

The custom header image, app gpg public key, ossec gpg public key and the smtp's CA cert need to be either in the install_files/ansible-base directory or the respective role's file directory
This is not true, Ansible's file module can take absolute paths so the files can be anywhere on the host's filesystem. This is fine for now, but I don't like the idea of mixing instance-dependent data into the repo. IMHO it would be better to provide absolute paths to something outside the repo. There are a lot of options here, and we should figure out the ergonomics as we test installations from the admin workstation today.