Travis: test against PHP 7.4, not snapshot
Travis: test against PHP 7.4, not snapshot

Looks like Travis (finally) has got a "normal" PHP 7.4 image available.

squizlabs/PHP_CodeSniffer,jrfnl/PHP_CodeSniffer,stronk7/PHP_CodeSniffer,jrfnl/PHP_CodeSniffer,stronk7/PHP_CodeSniffer,squizlabs/PHP_CodeSniffer,stronk7/PHP_CodeSniffer,squizlabs/PHP_CodeSniffer,jrfnl/PHP_CodeSniffer