コマンド

$ phpbrew install 7.1.23 +default+dbs
$ phpbrew use 7.1.23 #一時的に使う
$ phpbrew switch 7.1.23 #ずっと使う

参考

Laravel 5.2 Requirements

PHP version between 5.5.9 - 7.1.*
OpenSSL PHP Extension
PDO PHP Extension
Mbstring PHP Extension
Tokenizer PHP Extension

phpbrew variants

default:    bcmath, bz2, calendar, cli, ctype, dom, fileinfo, filter, ipc,
              json, mbregex, mbstring, mhash, mcrypt, pcntl, pcre, pdo, phar,
              posix, readline, sockets, tokenizer, xml, curl, openssl, zip
dbs:        sqlite, mysql, pgsql, pdo