update php version and tests

Author: noogen

.travis.yml

@@ -1,8 +1,8 @@
 language: php
 php:
-  - '7.2'
   - '7.3'
   - '7.4'
+  - '8.0'
 
 sudo: false
 

composer.json

@@ -26,10 +26,10 @@
   }],
   "type": "library",
   "require": {
-    "php": ">=7.2"
+    "php": ">=7.3"
   },
   "require-dev": {
-    "phpunit/phpunit": "^8.0"
+    "phpunit/phpunit": "^9.5.0"
   },
   "autoload": {
     "psr-4": {
@@ -45,5 +45,10 @@
     "prefer-install": "dist"
   },
   "minimum-stability": "dev",
-  "prefer-stable": true
+  "prefer-stable": true,
+  "scripts": {
+    "test": [
+        "phpunit tests/*.php"
+    ]
+  }
 }