Lot of updates need to be done on the documentation. I have run into many issues, but managed to get around some of them.
One of them not so much,
yum install php71-php-pear php71-php-pecl-mongo php71u-cli php71u-mysqlnd php71-php-devel
Returns:
No package php71-php-pear available.
No package php71-php-pecl-mongo available.
No package php71u-cli available.
No package php71u-mysqlnd available.
No package php71-php-devel available.
A yum search of something even similar reveals no such packages.