How can I install a specific version of the docker engine

Found a way that works at least for 1.7.X versions and above using the deb repository at:
https://apt.dockerproject.org/repo/pool/main/d/docker-engine

Installing docker now using:

wget -O docker.deb https://apt.dockerproject.org/repo/pool/main/d/docker-engine/docker-engine_1.7.1-0~trusty_amd64.deb 
sudo dpkg -i docker.deb