Create Experiment Orchestrator to manage experiment state

[WillieCubed]

At the highest level, the ExperimentOrchestrator is a test harness keeps track of experiments running in memory and allows high-level mechanisms to manage experiment state. It will be able to:

• [ ] Provision (create) an experiment instance from a given configuration
• [ ] Start/stop a given experiment
• [ ] Generate reports/logs for what happened during given experiment

As a note, the ExperimentOrchestrator currently does not persist data across server restarts; it only manages actively running or recently finished experiments.

For now, we'll ignore error handling.