Debug token map handling

[blink1073]

Strip whitespace from the token and print the last five characters for debugging purposes.

[codecov-commenter]

Codecov Report

Merging #173 (bcd8a6e) into master (47c293c) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #173   +/-   ##
=======================================
  Coverage   85.51%   85.51%           
=======================================
  Files          17       17           
  Lines        2161     2161           
  Branches      262      262           
=======================================
  Hits         1848     1848           
  Misses        220      220           
  Partials       93       93           

Impacted Files	Coverage Δ
jupyter_releaser/python.py	87.50% <100.00%> (ø)

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[blink1073]

cc @davidbrochart this will help us debug if you hit a snag releasing again