update repo and install composer
$ sudo apt-get update
$ sudo apt-get install curl php5-cli git
$ curl -sS https://getcomposer.org/installer | sudo php — –install-dir=/usr/local/bin –filename=composer
test it
$ composer
update
$ cd /usr/share/nginx/html/kamp/
$ composer update
if you see the following error
PHP Fatal error: Uncaught exception ‘ErrorException’ with message ‘proc_open(): fork failed – Cannot allocate memory’ in phar
$ sudo /bin/dd if=/dev/zero of=/var/swap.1 bs=1M count=1024
$ sudo /sbin/mkswap /var/swap.1
$ sudo /sbin/swapon /var/swap.1
update
$ composer update