ci: add php 8 support (#13)

- adds php 8 support
- removes package-versions
- updates dependencies

Fixes #8

.github/workflows/phpunit.yml

@@ -17,6 +17,7 @@ jobs:
         php-version:
           - 7.3
           - 7.4
+          - 8.0
         operating-system:
           - ubuntu-latest
 

.gitignore

@@ -3,3 +3,4 @@
 /coveralls-upload.json
 /phpunit.xml
 /vendor/
+.phpunit.result.cache

composer.json

@@ -7,16 +7,15 @@
   ],
   "license": "MIT",
   "require": {
-    "php": "^7.2",
-    "ocramius/package-versions": "^1.3",
+    "php": "^7.3 || ^8.0",
     "psr/container": "^1.0",
     "symfony/console": "^4.0 || ^5.0"
   },
   "require-dev": {
     "laminas/laminas-coding-standard": "^2.0",
     "phpspec/prophecy-phpunit": "^2.0",
     "phpstan/phpstan": "^0.12",
-    "phpunit/phpunit": "^9.2"
+    "phpunit/phpunit": "^9.5"
   },
   "config": {
     "sort-packages": true