Several python scripts will need to be made to automate the manual process of creating a virtual env with a known location, installing the dependencies, checking dependencies installed match the requirements file, and removing the virtual environment.

This allows us to have full programmatic control over the virtual environment.
Because pip is quite slow, we can detect that dependencies have change simply by caching / copying the requirements file during install. If the files don't match, the deps have changed since the last installation of dependencies. Developers will need to be able to downgrade dependences (Eg when checking out beta after having master), pip doesn't support this well. To support this in a simple and reliable way, we can just delete the virtual environment, and re-install the dependencies from the (updated) requirements file. Because the packages are cached, this should be a fairly quick operation.

For now these can be left for developers to run manually. Point to these from the docs.