upgrading scripts for CentOS 7

	add GPG keys for REMI and EPEL rpms
	update nginx version to latest
	update nginx build arguments based on CentOS 7 package manager version
	change /var/run to /run for nginx PID variable
	change SELECTED_ZONE to DEFAULT_ZONE variable name

 On branch centos7
 Changes to be committed:

	modified:   scripts/firewalld.sh
	modified:   scripts/lemp.sh
	modified:   scripts/linux_update.sh
	modified:   scripts/nginx_config.sh
	modified:   setup.sh