Update Dingding QR code.

[CasperLiu]

Fix #95

[codecov-io]

Codecov Report

Merging #96 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master     #96   +/-   ##
======================================
  Coverage    6.25%   6.25%           
======================================
  Files          31      31           
  Lines        4383    4383           
======================================
  Hits          274     274           
  Misses       4093    4093           
  Partials       16      16           

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[BSWANG]

LGTM