capital W and P, i guess, dangit

tests/phpunit/test-pantheon-updates.php

@@ -187,7 +187,7 @@ private static function is_prerelease() {
 			return false;
 		}
 
-		// If the version derived from wordpress is higher than the version in the wp-version.json file, then we're using a prerelease.
+		// If the version derived from WordPress is higher than the version in the wp-version.json file, then we're using a prerelease.
 		if ( version_compare( $current_version, $installed_version, '>' ) ) {
 			return true;
 		}