Revert to a clean master

[azagniotov]

Reverting three (3) last PRs:

• Introduced on CircleCI a multi-arch Docker image build using BuildX #465
• Fixing buildx in config.yml #464
• Changes to config.yml to test the docker buildx #463

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (6f09ed9) 96.94% compared to head (51827c5) 96.94%.

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Additional details and impacted files

@@            Coverage Diff            @@
##             master     #467   +/-   ##
=========================================
  Coverage     96.94%   96.94%           
  Complexity      820      820           
=========================================
  Files            65       65           
  Lines          2681     2681           
  Branches        279      279           
=========================================
  Hits           2599     2599           
  Misses           49       49           
  Partials         33       33