Update deps

Author: sebastiandedeyne

composer.json

@@ -31,11 +31,11 @@
     ],
     "require": {
         "php" : "^7.0",
-        "illuminate/support": "5.5.x-dev",
+        "illuminate/support": "~5.5.0",
         "nesbot/carbon": "^1.0"
     },
     "require-dev": {
-        "orchestra/testbench": "3.5.x-dev",
+        "orchestra/testbench": "~3.5.0",
         "phpunit/phpunit": "^6.0",
         "spatie/phpunit-snapshot-assertions": "^1.0"
     },
@@ -58,7 +58,5 @@
                 "Spatie\\Feed\\FeedServiceProvider"
             ]
         }
-    },
-    "minimum-stability": "dev",
-    "prefer-stable": true
+    }
 }