Using Docker Machine as your development environment
Not only is Polis a multi node system, but building and running Docker images can place quite a strain on smaller machines, both in terms of memory and hard drive footprint.
If you have a small machine or little hard drive space, you may want to consider using Docker-Machine as a development environment. This solution lets you run a Polis development environment (as described in the README) in the cloud, so you can save your local resources.
You can follow this tutorial for an overview of how to take advantage of Digital Ocean for these purposes (DigitalOcean with 2GB memory should be sufficient):
Once you have things running, you'll want to check your IP address, as you'll need this to interact with your development environment:
docker-machine ip
>>> 123.45.67.89
In this case, you would visit your instance at: http://123.45.67.89.sslip.io/
The directions in the README should get you the rest of the way. Good luck!