* Upgrade to latest debian base image
* Upgrade to Notebook 4.3
* Upgrade to Miniconda 4.2.12
* Remove USE_HTTPS env var in favor of command line options for key and cert
* Add GEN_CERT env var for generating a self-signed certificate
* Remove PASSWORD env var in favor of the new Notebook 4.3 default token auth
or the more secure a hashed password command line option
As per [their blog post of the 27th April](https://blog.readthedocs.com/securing-subdomains/) ‘Securing subdomains’:
> Starting today, Read the Docs will start hosting projects from subdomains on the domain readthedocs.io, instead of on readthedocs.org. This change addresses some security concerns around site cookies while hosting user generated data on the same domain as our dashboard.
Test Plan: Manually visited all the links I’ve modified.