Log Message:
py-simpy: updated to 3.0.11

3.0.11:
- [FIX] Repair Environment.exit() to support PEP-479 and Python 3.7.
- [FIX] Fix wrong usage_since calculation in preemptions
- [NEW] Add "Time and Scheduling" section to docs
- [CHANGE] Move Interrupt from events to exceptions
- [FIX] Various minor documentation improvements