replace clock from time

[sbenthall]

Many places in the library use

from time import clock

This has been deprecated since Python 3.3 and officially removed as of Python 3.8
Since Dolo requires 3.8, getting the library ready for 3.8 compatibility is important for maintaining joint environments.

The functions are recommended instead:

https://docs.python.org/3/library/time.html#time.process_time

https://docs.python.org/3/library/time.html#time.perf_counter

[sbenthall]

Maybe this is just in a couple example notebooks....

examples/Gentle-Intro/Gentle-Intro-To-HARK.py

examples/ConsIndShockModel/IndShockConsumerType.ipynb