Generate a Run ID via API#125

Be able to generate a Run ID via an API call. Then we can use the Run ID to send output from parallel test runs. There should also be a call to “end” the Run (based on the Run ID) that would then trigger any notifications.

A similar set of API calls for a Run Group would be useful - or at least the ability to trigger the notification to be sent when all the runs from a Run Group are finished. Then there could be a unified Run Group report sent out as a single notification.