Remove contracts dependency because it contains in support already

Author: antonkomarev

composer.json

@@ -40,7 +40,6 @@
     "require": {
         "php": "^7.1.3",
         "ext-json": "*",
-        "illuminate/contracts": "5.6.*|5.7.*|5.8.*",
         "illuminate/support": "5.6.*|5.7.*|5.8.*",
         "mcstreetguy/composer-parser": "^1.0"
     },