Install Debian Jessie on DigitalOcean using the Debian 7.0 x64 Image.
First update to Debian 8.0 Jessie:
# Source:
# http://unix.stackexchange.com/questions/90389/how-to-upgrade-debian-stable-wheezy-to-testing-jessie/90391#90391
cp /etc/apt/sources.list{,.bak}
sed -i -e 's/ \(stable\|wheezy\)/ testing/ig' /etc/apt/sources.list
apt-get update