PHPCompatibility v10

[tomjn]

It's currently in alpha, but it should fix a common issue with WPCS we're seeing, e.g.

------------------------------------------------------------------------------------------------------------------------------------------------------
FOUND 1 ERROR AFFECTING 1 LINE
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 1 | ERROR | An error occurred during processing; checking has been aborted. The error message was: trim(): Passing null to parameter #1 ($string) of
   |       | type string is deprecated in /Users/tomjn/dev/PHPBasicAuth/vendor/phpcompatibility/php-compatibility/PHPCompatibility/Sniff.php on line
   |       | 131
   |       | The error originated in the .PHPCompatibility. sniff on line 131. (Internal.Exception)
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[tomjn]

Related to #313

[tomjn]

https://github.com/PHPCompatibility/PHPCompatibility/wiki/Upgrading-to-PHPCompatibility-10.0#updating-your-custom-ruleset-and-phpcs-ignore-annotations