Make composer works on Digital Ocean
When we try to install/update some stuff with composer, anyway we put -1 memory (or +1000) it still not working, to solve this we can create a swap file.
Here is the trick:
mkdir -p /var/_swap_
#Here, 1M * 2000 ~= 2GB of swap memory
dd if=/dev/zero of=swapfile bs=1M count=2000
swapon swapfile chmod 600 swapfile
echo "/var/_swap_/swapfile none swap sw 0 0" >> /etc/fstab