Update codestyle for Python 3.6

[simondeziel]

No description provided.

[codecov-commenter]

Codecov Report

Merging #541 (3957a50) into master (fe37358) will not change coverage.
The diff coverage is 94.73%.

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@@           Coverage Diff           @@
##           master     #541   +/-   ##
=======================================
  Coverage   97.43%   97.43%           
=======================================
  Files          56       56           
  Lines        4251     4251           
=======================================
  Hits         4142     4142           
  Misses        109      109           

Impacted Files	Coverage Δ
pylxd/__init__.py	100.00% <ø> (ø)
pylxd/deprecated/operation.py	88.23% <ø> (ø)
pylxd/exceptions.py	50.00% <ø> (ø)
pylxd/deprecated/hosts.py	86.25% <80.00%> (ø)
pylxd/deprecated/image.py	97.77% <95.00%> (ø)
pylxd/client.py	90.17% <100.00%> (ø)
pylxd/deprecated/certificate.py	100.00% <100.00%> (ø)
pylxd/deprecated/connection.py	88.69% <100.00%> (ø)
pylxd/deprecated/container.py	92.22% <100.00%> (ø)
pylxd/deprecated/exceptions.py	100.00% <100.00%> (ø)
... and 6 more

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