Allow failures for PHP nightly.
Allow failures for PHP nightly.

Currently PHPUnit is failing on PHP nightly and therefore the build is failing.

This change will prevent complete builds failing for failures which occur only in PHP nightly.

stronk7/PHP_CodeSniffer,VANINUitgeverij/PHP_CodeSniffer,jrfnl/PHP_CodeSniffer,jrfnl/PHP_CodeSniffer,VANINUitgeverij/PHP_CodeSniffer,arnested/PHP_CodeSniffer,fabacino/PHP_CodeSniffer,rcarraretto/PHP_CodeSniffer,fabacino/PHP_CodeSniffer,stronk7/PHP_CodeSniffer,rcarraretto/PHP_CodeSniffer,rcarraretto/PHP_CodeSniffer,squizlabs/PHP_CodeSniffer,arnested/PHP_CodeSniffer,jrfnl/PHP_CodeSniffer,stronk7/PHP_CodeSniffer,rcarraretto/PHP_CodeSniffer,arnested/PHP_CodeSniffer,fabacino/PHP_CodeSniffer,squizlabs/PHP_CodeSniffer,VANINUitgeverij/PHP_CodeSniffer,squizlabs/PHP_CodeSniffer