Output dir structure

Each new scenario's outputs are now placed in their own directory to prevent accidentally overwriting previous results.

A new output directory is created with each instance of the Setup() class.

The Setup() class contains all of the directory and file names for the outputs.

New to this release is a work-in-progress mapping module. This might well become a class in a future release.

Split national / selected unit data

🧹 Assorted refactoring of Scenario class.

Split the national stroke unit data (used to set up selected unit data) from the selected unit data (accessible during the simulation).

Saving more outputs to file.

Restructure code

Restructure code to run from root directory, and remove simple SimPy example.

Bug fixes

0.1.1

Update single test to run time = days

First release

Framework code up to ambulance response.