wp core install --url=example.com --title=WP-EXAMPLE --admin_user=******* --admin_password=****** --admin_email=******

Error: Error establishing a database connection. This either means that the username and password information in your `wp-config.php` file is incorrect or we can’t contact the database server at `localhost`. This could mean your host’s database server is down.

OS: Darwin 17.6.0 Darwin Kernel Version 17.6.0: Tue May  8 15:22:16 PDT 2018; root:xnu-4570.61.1~1/RELEASE_X86_64 x86_64
Shell:  /bin/zsh
PHP binary: /usr/bin/php
PHP version:    7.1.16
php.ini used:
WP-CLI root dir:    phar://wp-cli.phar
WP-CLI vendor dir:  phar://wp-cli.phar/vendor
WP_CLI phar path:   /Users/admin/code/wp-example
WP-CLI packages dir:
WP-CLI global config:
WP-CLI project config:
WP-CLI version: 1.5.1