Resolve Python 3.8 compatibility issues

[jsiirola]

Fixes: #65

Summary/Motivation:

Python 3.8 is out and is inducing some changes to PyUtilib.

Changes proposed in this PR:

• Adding 3.8 baselines
• Resolving use of the (now removed) time.clock
• minor syntax cleanup

Legal Acknowledgement

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[coveralls]

Coverage increased (+0.3%) to 61.845% when pulling 33d7ec2 on py38-fixes into cde4bee on master.

[codecov-io]

Codecov Report

Merging #66 into master will increase coverage by 0.25%.
The diff coverage is 25%.

@@            Coverage Diff             @@
##           master      #66      +/-   ##
==========================================
+ Coverage   62.57%   62.83%   +0.25%     
==========================================
  Files          87       87              
  Lines        8749     8775      +26     
==========================================
+ Hits         5475     5514      +39     
+ Misses       3274     3261      -13

Impacted Files	Coverage Δ
pyutilib/misc/timing.py	0% <0%> (ø)	⬆️
pyutilib/ply/ply.py	23.33% <0%> (ø)	⬆️
pyutilib/workflow/functor.py	97.51% <100%> (ø)	⬆️
pyutilib/subprocess/processmngr.py	60.34% <100%> (+0.11%)	⬆️
pyutilib/th/pyunit.py	47.45% <0%> (-0.49%)	⬇️
pyutilib/autotest/driver.py	72.8% <0%> (+0.1%)	⬆️
pyutilib/component/core/core.py	84.73% <0%> (+0.11%)	⬆️
pyutilib/misc/archivereader.py	82.01% <0%> (+0.39%)	⬆️
pyutilib/pyro/worker.py	15.18% <0%> (+0.42%)	⬆️
... and 3 more

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