Upgrade tests tools (#32)

* Upgrade friendsofphp/php-cs-fixer (v2.7.1 => v2.15.0)

* Upgrade scrutinizer/ocular (1.4.0 => 1.5.2)

* Upgrade guzzlehttp/guzzle (6.3.0 => 6.3.3)

Author: slavcodev

composer.json

@@ -25,9 +25,9 @@
     }
   },
   "require-dev": {
-    "guzzlehttp/guzzle": "~6.2",
-    "scrutinizer/ocular": "~1.1",
-    "friendsofphp/php-cs-fixer": "~2.0"
+    "guzzlehttp/guzzle": "^6.3.3",
+    "scrutinizer/ocular": "^1.5.2",
+    "friendsofphp/php-cs-fixer": "^2.15"
   },
   "autoload-dev": {
     "psr-4": {