Updated PHP version for PHP7.2+

Removed PHP5 (no longer supported)
Renamed PHP7 to PHP - consistent with other kata
Added the same helpers as other PHP Kata
Updated the code to PHP7.2+ standard
Didn't change GildedRose updateQuality method
Updated GildedRoseTest (still failing)
Added ApprovalTest (passing)
- same text file as texttests / ThirtyDays / stdout.gr (only renamed).

php5/src/texttest_fixture.php

@@ -1,35 +0,0 @@
-<?php
-
-require_once 'gilded_rose.php';
-
-echo "OMGHAI!\n";
-
-$items = array(
-    new Item('+5 Dexterity Vest', 10, 20),
-    new Item('Aged Brie', 2, 0),
-    new Item('Elixir of the Mongoose', 5, 7),
-    new Item('Sulfuras, Hand of Ragnaros', 0, 80),
-    new Item('Sulfuras, Hand of Ragnaros', -1, 80),
-    new Item('Backstage passes to a TAFKAL80ETC concert', 15, 20),
-    new Item('Backstage passes to a TAFKAL80ETC concert', 10, 49),
-    new Item('Backstage passes to a TAFKAL80ETC concert', 5, 49),
-    // this conjured item does not work properly yet
-    new Item('Conjured Mana Cake', 3, 6)
-);
-
-$app = new GildedRose($items);
-
-$days = 2;
-if (count($argv) > 1) {
-    $days = (int) $argv[1];
-}
-
-for ($i = 0; $i < $days; $i++) {
-    echo("-------- day $i --------\n");
-    echo("name, sellIn, quality\n");
-    foreach ($items as $item) {
-        echo $item . PHP_EOL;
-    }
-    echo PHP_EOL;
-    $app->update_quality();
-}