Fix deprecation on tests, fix incomplete test, fix PHPUnit compat

Author: damienalexandre

src/Checker/JsonSorter.php

@@ -38,7 +38,7 @@ public function recursiveAlphabeticalSort($item)
 
                 if ('parameters' === $key) {
                     usort($asArray['parameters'], function ($a, $b) {
-                        return isset($a['name']) && isset($b['name']) && $a['name'] > $b['name'];
+                        return (isset($a['name']) && isset($b['name']) && $a['name'] > $b['name']) ? 1 : 0;
                     });
                 }
             }

tests/ReadingTest.php

@@ -124,7 +124,6 @@ public function testItCanSearchMessages()
         ]);
 
         self::assertInstanceOf(SearchMessagesGetResponse200::class, $results);
-
-        self::markTestIncomplete('The response is not tested as it is not specified!');
+        self::assertTrue($results->getOk());
     }
 }

tests/WritingTest.php

@@ -36,7 +36,12 @@ public function testItCanPostAttachment()
         ]);
 
         self::assertInstanceOf(ChatPostMessagePostResponse200::class, $response);
-        self::assertStringContainsString($response->getMessage()->getAttachments()[0]->getImageUrl(), 'https://jolicode.com/images/valeurs_huma.png');
+
+        if (method_exists($this, 'assertStringContainsString')) {
+            self::assertStringContainsString($response->getMessage()->getAttachments()[0]->getImageUrl(), 'https://jolicode.com/images/valeurs_huma.png');
+        } else {
+            self::assertContains($response->getMessage()->getAttachments()[0]->getImageUrl(), 'https://jolicode.com/images/valeurs_huma.png');
+        }
     }
 
     public function testItCanPostMessageWithBlock()