Made the template a cookiecutter and update the template with docs etc

@rknegjens Here is the cookiecutter version of the template. I made also some changes to the Makefile etc for how I like to have things but we don't necessarily need to do that. I also kept a pure folder which people can copy and manually edit if they don't want to use cookiecutter but we can also remove this depending on what you think.

One thing I'm wondering how to do the best is how we should tell people to specify the --extra-index-url. We could in the Makefile look for environment variables (eg. NSPIP_USER and NSPIP_PASSWORD) or alternatively suggest that the user should add a pip.conf while with this flag.

closes #11 (closed) closes #1 (closed)