Update unicode_numeric_hex.py with Python 3.9's Unicode Database

[swt2c]

Fixes #118.

[codecov]

Codecov Report

Merging #119 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #119   +/-   ##
=======================================
  Coverage   99.53%   99.53%           
=======================================
  Files          10       10           
  Lines         431      431           
=======================================
  Hits          429      429           
  Misses          2        2           

Impacted Files	Coverage Δ
natsort/unicode_numeric_hex.py	100.00% <ø> (ø)

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[SethMMorton]

Maybe the .travis-ci.yml should be updated to run Python 3.9 as well?