chore: remove wercker yml file

[thinkerou]

Now the wercker.yml have no longer used.

[codecov]

Codecov Report

Merging #1676 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1676   +/-   ##
=======================================
  Coverage   99.39%   99.39%           
=======================================
  Files          41       41           
  Lines        1993     1993           
=======================================
  Hits         1981     1981           
  Misses          9        9           
  Partials        3        3

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