Added minimal GitHub CI tests

Author: MekDrop

.github/workflows/test.yml

@@ -0,0 +1,43 @@
+name: Tests
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  run:
+    runs-on: ubuntu-latest
+    continue-on-error: false
+    strategy:
+      max-parallel: 3
+      matrix:
+        php:
+          - 7.2
+          - 7.3
+          - 7.4
+          - 8.0
+          - 8.1
+        composer: 
+          - 2  
+    name: Test - php:${{ matrix.php }}; composer:${{ matrix.composer }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@master
+      - name: Install PHP
+        uses: shivammathur/setup-php@master
+        with:
+          php-version: ${{ matrix.php }}
+          extensions: curl, gd, pdo_mysql, json, mbstring, pcre, session
+          ini-values: post_max_size=256M
+          coverage: none
+          tools: composer:v${{ matrix.composer }}
+      - name: Composer validate
+        run: composer validate --strict --no-check-lock
+      - name: Install Composer dependencies (with dev)
+        run: composer install --no-progress --no-suggest --prefer-dist --optimize-autoloader
+      - name: Install Composer dependencies (without dev)
+        run: composer install --no-progress --no-dev --no-suggest --prefer-dist --optimize-autoloader