added CI

.gitlab-ci.yml

+stages:
+  - test
+
+verify-7.4:
+  image: grifart/php7.4-with-all-modules-and-various-tools
+  stage: test
+  interruptible: true
+
+  script:
+    - composer install
+    - composer run verify
+
+verify-8.0:
+  image: grifart/php8.0-with-all-modules-and-various-tools
+  stage: test
+  interruptible: true
+
+  script:
+    - composer install
+    - composer run verify
+
+
+verify-8.1:
+  image: grifart/php8.1-with-all-modules-and-various-tools
+  stage: test
+  interruptible: true
+
+  script:
+    - composer install
+    - composer run verify

composer.json

@@ -3,11 +3,12 @@
     "description": "Let everyone know, that this class has not been meant for serialization.",
     "type": "library",
     "scripts": {
+        "verify": ["@test", "@phpstan"],
         "test": "tester tests",
         "phpstan": "phpstan analyze -l 9 src tests"
     },
     "require": {
-        "php": ">=8.1"
+        "php": ">=7.4"
     },
     "require-dev": {
         "nette/tester": "^2.4",