Allow "rawr/cross-data-providers" version compatible with PHP 7.0

This version supposedly supports PHP 5.6,
but seems to have different class names, so is not compatible.

Instead, on 5.6, mark tests as skipped if they can't be run.

Author: JakeQZ

composer.json

@@ -28,7 +28,7 @@
     },
     "require-dev": {
         "phpunit/phpunit": "5.7.27 || 6.5.14 || 7.5.20 || 8.5.41",
-        "rawr/cross-data-providers": "2.4.0"
+        "rawr/cross-data-providers": "^2.0.0"
     },
     "suggest": {
         "ext-mbstring": "for parsing UTF-8 CSS"

tests/Unit/Position/PositionTest.php

@@ -184,6 +184,11 @@ public function setPositionWithNullForColumnNumberClearsColumnNumber()
      */
     public function provideLineAndColumnNumber()
     {
+        if (!\class_exists(DataProviders::class)) {
+            self::markTestSkipped('`DataProviders` class is not available');
+            return [];
+        }
+
         return DataProviders::cross($this->provideLineNumber(), $this->provideColumnNumber());
     }