Require Laravel 5.8

composer.json

@@ -11,10 +11,10 @@
     ],
     "license" : "MIT",
     "require": {
-        "illuminate/support": "^5.6",
-        "illuminate/container": "^5.6",
-        "illuminate/database": "^5.6",
-        "illuminate/events": "^5.6",
+        "illuminate/support": "^5.8",
+        "illuminate/container": "^5.8",
+        "illuminate/database": "^5.8",
+        "illuminate/events": "^5.8",
         "mongodb/mongodb": "^1.0.0"
     },
     "require-dev": {