Bump min. PHP version to 8 and fix tests

Author: ekinhbayar

.gitignore

@@ -2,3 +2,4 @@
 /public/.htaccess
 config.php
 vendor
+.phpunit.result.cache

.scrutinizer.yml

@@ -24,8 +24,8 @@ tools:
     php_pdepend:
         enabled: true
         excluded_dirs: ["test", "vendor"]
-    php_analyzer: true
     php_analyzer:
+        enabled: true
         filter:
             paths: ["src/*", "test/*"]
     sensiolabs_security_checker: true

.travis.yml

@@ -1,8 +1,8 @@
 language: php
 
 php:
-  - "7.0"
-  - "7.1"
+  - "8.0"
+  - "8.1"
   - "nightly"
 
 before_script:

composer.json

@@ -13,9 +13,9 @@
         }
     ],
     "require": {
-        "php": "^7"
+        "php": "^8"
     },
     "require-dev": {
-        "phpunit/phpunit": "^6"
+        "phpunit/phpunit": "^9"
     }
 }