Update phpunit to 6.5

Update Slim to 3.9

composer.json

@@ -5,7 +5,7 @@
   "homepage": "http://alltubedownload.net/",
   "type": "project",
   "require": {
-    "slim/slim": "~3.8.1",
+    "slim/slim": "~3.9.2",
     "mathmarques/smarty-view": "~1.1.0",
     "symfony/yaml": "~3.3.9",
     "symfony/process": "~3.3.9",
@@ -21,7 +21,7 @@
   "require-dev": {
     "symfony/var-dumper": "~3.3.9",
     "squizlabs/php_codesniffer": "~3.1.0",
-    "phpunit/phpunit": "~6.4.3",
+    "phpunit/phpunit": "~6.5.2",
     "doctrine/instantiator": "~1.0.0",
     "ffmpeg/ffmpeg": "dev-release",
     "rg3/youtube-dl": "2017.11.06",