Add Laravel 7 compatibility.

composer.json

@@ -8,18 +8,23 @@
             "email": "hello@genealabs.com"
         }
     ],
+    "repositories": [
+        {
+            "type": "vcs",
+            "url": "https://github.com/GeneaLabs/model"
+        }
+    ],
     "require": {
-        "illuminate/support": "^6.0",
-        "illuminate/session": "^6.0",
-        "jenssegers/model": "^1.2"
+        "illuminate/support": "^7.0",
+        "illuminate/session": "^7.0",
+        "jenssegers/model": "dev-master@dev"
     },
     "require-dev": {
-        "laravel/laravel": "^6.0",
-        "mockery/mockery": "^1.0",
+        "laravel/laravel": "dev-develop@dev",
         "phpmd/phpmd": "^2.7",
-        "phpunit/phpunit": "^8.0",
+        "phpunit/phpunit": "^8.5",
         "php-coveralls/php-coveralls" : "^2.2",
-        "sebastian/phpcpd": "^4.1"
+        "sebastian/phpcpd": "^5.0"
     },
     "autoload": {
         "psr-4": {