Support Laravel 7; Drop 5.8

Author: iv-craig

composer.json

@@ -13,14 +13,14 @@
     ],
     "require": {
         "php": "^7.2",
-        "illuminate/notifications": "5.8.*|^6.0",
-        "illuminate/support": "5.8.*|^6.0",
+        "illuminate/notifications": "^6.0|^7.0",
+        "illuminate/support": "^6.0|^7.0",
         "interfax/interfax": "^1.1"
     },
     "require-dev": {
         "mockery/mockery": "^1.0",
         "mpdf/mpdf": "^8.0",
-        "orchestra/testbench": "~3.8|~4.0",
+        "orchestra/testbench": "~4.0|~5.0",
         "phpunit/phpunit": "^8.0"
     },
     "autoload": {