Provide support for long running, time based tests

[travisbenedict]

Is your feature request related to a problem? Please describe.

It would be useful to be able to run tests for a specified amount of time in order to test the stability of a cluster over time. My specific use case would be for generating load against a cluster for several days at a time.

Describe the solution you'd like

Run a given workload for a specified amount of time. This could be accomplished by repeating the same workload over and over until the time limit is reached.

Describe alternatives you've considered

Run a given workload for a specified amount in immediate succession. This allows for testing similar use cases but is not as specific since one has to have an estimate of how long a workload takes to run on their specific cluster configuration.

Additional context

N/A