Some more updates for python 3 language changes, tidyups

[marksmayo]

With your PR, here is a check list:

• [NA ] Has test cases written?
• [ Y] Has all code lines tested?
• [N - doesn't run on windows ] Has make format been run?
• Please update CHANGELOG.yml(not CHANGELOG.rst)
• [NA ] Has fair amount of documentation if your change is complex
• [ Y] Agree on NEW BSD License for your contribution

[codecov-commenter]

Codecov Report

Merging #276 (a6e916f) into dev (ee0722a) will decrease coverage by 0.01%.
The diff coverage is 97.01%.

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@@            Coverage Diff             @@
##              dev     #276      +/-   ##
==========================================
- Coverage   98.42%   98.42%   -0.01%     
==========================================
  Files          98       98              
  Lines        6714     6711       -3     
==========================================
- Hits         6608     6605       -3     
  Misses        106      106              

Impacted Files	Coverage Δ
pyexcel/__init__.py	100.00% <ø> (ø)
pyexcel/docstrings/__init__.py	100.00% <ø> (ø)
pyexcel/docstrings/keywords.py	100.00% <ø> (ø)
pyexcel/plugins/parsers/__init__.py	100.00% <ø> (ø)
pyexcel/plugins/parsers/django.py	93.75% <ø> (ø)
pyexcel/plugins/parsers/excel.py	100.00% <ø> (ø)
pyexcel/plugins/parsers/sqlalchemy.py	93.75% <ø> (ø)
pyexcel/plugins/renderers/__init__.py	100.00% <ø> (ø)
pyexcel/plugins/sources/db_sources.py	94.36% <ø> (ø)
pyexcel/plugins/sources/django.py	100.00% <ø> (ø)
... and 54 more

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[marksmayo]

Hit my limit here. Not sure how to fix last issues in win.