Add Laravel 7 support

Author: ssx

README.md

@@ -5,7 +5,7 @@
 
 # Laravel Validator Rules - Timezone
 
-This rule will validate that a given timezone is valid within the systems datetime database.
+This rule will validate that a given timezone is valid within the systems date-time database.
 
 ### License
 This project is licensed under an Apache 2.0 license which you can find

composer.json

@@ -12,11 +12,11 @@
         }
     ],
     "require": {
-        "illuminate/validation": "^5.5|^6.0",
-        "illuminate/translation": "^5.5|^6.0"
+        "illuminate/validation": "^5.5|^6.0|^7.0",
+        "illuminate/translation": "^5.5|^6.0|^7.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "~5.7"
+        "phpunit/phpunit": "~5.7|^9.0"
     },
     "autoload": {
         "psr-4": {