simplify working directories

	mkdir -p repos, build, and rpm_keys in setup.sh
	use $HOME to save downloads and work with setup
	only the Middleman and Server_ssh scripts use /home/$USER_NAME to configure settings for the new SSH user and Middleman project
	create function for importing RPM GPG keys

On branch centos7
Changes to be committed:

	modified:   init.sh
	modified:   scripts/aliases.sh
	modified:   scripts/lemp.sh
	modified:   scripts/linux_update.sh
	modified:   scripts/middleman.sh
	modified:   scripts/server_ssh.sh
	modified:   scripts/wordpress_install.sh
	modified:   setup.sh