Update to Vim8 on Centos 7

Upgrade vim

# You may use this CentOS 7 repository on Fedora Copr for Vim 8 builds.
#      https://copr.fedorainfracloud.org/coprs/mcepl/vim8/
#
#  Run these commands on CentOS 7.

# Add this repository:

sudo curl -L https://copr.fedorainfracloud.org/coprs/mcepl/vim8/repo/epel-7/mcepl-vim8-epel-7.repo -o /etc/yum.repos.d/mcepl-vim8-epel-7.repo

# Upgrade Vim to vim 8:

sudo yum update vim*

# After it is successful, your Vim should be version 8.0 now:
vim --version

# You should see...
# VIM - Vi IMproved 8.0 (2016 Sep 12, compiled Aug  2 2017 16:29:21)
# Included patches: 1-839