Add phpstan config file

[ADmad]

No description provided.

[codecov]

Codecov Report

Merging #40 (1b7d710) into master (7aeff35) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master      #40   +/-   ##
=========================================
  Coverage     93.82%   93.82%           
  Complexity       54       54           
=========================================
  Files             1        1           
  Lines           178      178           
=========================================
  Hits            167      167           
  Misses           11       11           

Impacted Files	Coverage Δ
src/Model/Behavior/SequenceBehavior.php	93.82% <ø> (ø)

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