Incorrect PHP version requirement documentation

[chaslain]

The composer.json states that a version of php at 5.0 is required, but access modifiers exist on constants (i.e.) public const.

This is a feature that was added in php 7.1.

Example:

abstract class DOM implements Query, IteratorAggregate, Countable
{

	/**
	 * The array of matches.
	 */
	protected $matches = [];

	/**
	 * Default parser flags.
	 *
	 * These are flags that will be used if no global or local flags override them.
	 *
	 * @since 2.0
	 */
	public const DEFAULT_PARSER_FLAGS = null;

	public const JS_CSS_ESCAPE_CDATA = '\\1';
	public const JS_CSS_ESCAPE_CDATA_CCOMMENT = '/* \\1 */';
	public const JS_CSS_ESCAPE_CDATA_DOUBLESLASH = '// \\1';
	public const JS