Add sleep functionality to python_script

[raerae1616 (cajuncoding)]

For anyone else stumbling for information on Python Scripts and finding this thread, it’s important to mention that support for time.sleep() was in fact added . . . see this thread:

Python_script feedback

I’ve changed my mind. If people want to implement sleep, they can. We should just make sure we add a warning in the docs that you are blocking a limited amount of workers. A pull request to expose both the datetime and time modules is welcome.