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 so it will not mount the repo in the remote host (/vagrant).

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