Add a new blog a the end of planet/planetsympy/config. Send a PR against this repository. Travis tests must pass: Travis will build a docker image and pull all the blogs. This will ensure that the syntax in the config file is correct.

docker build -t username/planet-sympy:v1 .

docker run -d -e DEPLOY_TOKEN=XXX test/planet-sympy:v1

Where you change XXX for the password/key used to generate the deploykey.enc (see the README in the keys directory). This command will update the planet and push the new files into the https://github.com/planet-sympy/planet.sympy.org repository.