small size centos7 gui
1. Install CentOS-7 - Minimal (First entry point in list)
2. yum groupinstall "X Window System"
3. yum install gnome-classic-session gnome-terminal nautilus-open-terminal control-center liberation-mono-fonts
4. unlink /etc/systemd/system/default.target
5. ln -sf /lib/systemd/system/graphical.target /etc/systemd/system/default.target
6. reboot