Test up to PHP 8.1

Author: adbario

.github/workflows/tests.yml

@@ -9,10 +9,10 @@ jobs:
     continue-on-error: ${{ matrix.experimental }}
     strategy:
       matrix:
-        php: ['5.5', '5.6', '7.0', '7.1', '7.2', '7.3']
+        php: ['5.5', '5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1']
         experimental: [false]
         include:
-          - php: 7.2
+          - php: 8.1
             analysis: true
 
     steps:

.gitignore

@@ -1,5 +1,9 @@
-build
-vendor
+.DS_Store
 .idea
+.phpunit.result.cache
+.vscode
+clover.xml
 composer.lock
 phpunit.xml
+vendor
+coverage

.travis.yml

@@ -11,12 +11,12 @@
         }
     ],
     "require": {
-        "php": ">=5.5",
+        "php": "^5.5 || ^7.0 || ^8.0",
         "ext-json": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.0|^5.0|^6.0",
-        "squizlabs/php_codesniffer": "^3.0"
+        "phpunit/phpunit": "^4.8|^5.7|^6.6|^7.5|^8.5|^9.5",
+        "squizlabs/php_codesniffer": "^3.6"
     },
     "autoload": {
         "files": [