move analyse-paths into phpstan.neon

[staabm]

should fix

In InitialStaticAnalysisRunFailed.php line 29:
                                                                               
  Project static analysis must be in a passing state before running Infection  
  .                                                                            
  PHPStan reported an exit code of 1.                                          
  Refer to the PHPStan's output below:                                         
  STDERR:                                                                      
  At least one path must be specified to analyse.           

in phpstan/build-infection#15

[ondrejmirtes]

Thank you!