Install composer on Linux
curl https://getcomposer.org/installer > composer-setup.php
php composer-setup.php
php -r "unlink('composer-setup.php');"
sudo mv composer.phar /usr/local/bin/composer
apt install subversion
When using composer command, if you get error:
E230001: Server SSL certificate verification failed: issuer is not trusted
Fix: run this command
svn list https://svn.php.net/repository/phpdoc/en/trunk/reference
