Enable headless parameter testing

[jchesterpivotal]

In either the CLI or in the GUI (#14), simulations are performed one at a time using parameters selected by the user.

There are a lot of parameters that can be tinkered with and we may introduce more in future. Ideally, Skenario would have a facility for being run automatically over many parameter variations in order to explore the system envelope and potentially perform simple searches for optimal configurations and catastrophic configurations.

A score would be needed -- possibly "zero error".