Replace StyleCI with PHP CS Fixer

[mspirkov]

Q	A
Is bugfix?	❌
New feature?	❌
Breaks BC?	❌
Fixed issues

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.24%. Comparing base (4ddd7d0) to head (072ae22).
⚠️ Report is 9 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master      #56      +/-   ##
============================================
- Coverage     98.30%   98.24%   -0.06%     
  Complexity       20       20              
============================================
  Files             1        1              
  Lines            59       57       -2     
============================================
- Hits             58       56       -2     
  Misses            1        1              

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