Upgrade to WireViz 0.3.1

[amotl]

This patch could be used if wireviz/WireViz#254 makes it into the upstream code base. It will make wireviz.parse()'s file_out argument optional again.

[codecov]

Codecov Report

Merging #4 (d623ede) into main (7762be9) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##              main        #4   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            6         6           
  Lines          162       156    -6     
=========================================
- Hits           162       156    -6     

Flag	Coverage Δ
unittests	100.00% <ø> (ø)

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Impacted Files	Coverage Δ
wireviz_web/core.py	100.00% <ø> (ø)

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[amotl]

@formatc1702 said at wireviz/WireViz#254 (comment):

WireViz 0.3.1 has been released on PyPI, and it includes the hotfix

Thank you!