Install symfony/thanks

Author: socheatsok78

composer.json

@@ -25,7 +25,8 @@
     "illuminate/support": "~5.3.0|~5.4.0|~5.5.0|~5.6.0|~5.7.0|~5.8.0"
   },
   "require-dev": {
-    "orchestra/testbench": "^3.5"
+    "orchestra/testbench": "^3.5",
+    "symfony/thanks": "^1.1"
   },
   "autoload": {
     "psr-4": {