CentOS rbenv install for each user. (if they clone it)

.gemrc

# Consider putting this file in /etc/skel
# Avoid installing rdoc and ri by default
:update_sources: true
:sources:
- https://rubygems.org
:benchmark: false
:bulk_threshold: 1000
:backtrace: false
:verbose: true
gem: --no-ri --no-rdoc

rbenv.sh

# /etc/profile.d/rbenv.sh
# rbenv setup
if [ -d $HOME/.rbenv ]
  then
    export RBENV_ROOT="$HOME/.rbenv"
    export PATH="$RBENV_ROOT/bin:$PATH"
    eval "$(rbenv init -)"
fi

yum requirements

# This includes some dependencies needed for Rails and some related gems (libxml2-devel, libxslt-devel, boost-devel and sqlite-devel)

yum install gcc-c++ patch readline readline-devel zlib zlib-devel libyaml-devel libffi-devel openssl-devel \
  make bzip2 autoconf automake libtool bison psiconv-devel git libxml2-devel libxslt-devel boost-devel sqlite-devel bzip2-devel