The php-wpcli_1.4.0_all.deb depends on php7.0-mysql and php5-mysql, but not php7.1-mysql.
If you have PHP 7.1 installed and try to install this package, it fails:
dpkg -i php-wpcli_1.4.0_all.deb
Selecting previously unselected package php-wpcli.
(Reading database ... 224349 files and directories currently installed.)
Preparing to unpack php-wpcli_1.4.0_all.deb ...
Unpacking php-wpcli (1.4.0) ...
dpkg: dependency problems prevent configuration of php-wpcli:
php-wpcli depends on php5-mysql | php5-mysqlnd | php7.0-mysql; however:
Package php5-mysql is not installed.
Package php5-mysqlnd is not installed.
Package php7.0-mysql is not installed.
dpkg: error processing package php-wpcli (--install):
dependency problems - leaving unconfigured
Processing triggers for man-db (2.7.6.1-2) ...
Errors were encountered while processing:
php-wpcli