Replace Travis with GitHub actions

travis-ci.org does not run tests anymore

.github/workflows/ci.yml

@@ -0,0 +1,24 @@
+---
+name: Tests
+on:
+  - push
+  - pull_request
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php-version:
+          - '7.3'
+          - '7.4'
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use PHP ${{ matrix.php-version }}
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-version }}
+          tools: composer
+      - run: composer install --no-progress
+      - run: composer check-platform-reqs
+      - run: composer lint
+      - run: composer test

.travis.yml

@@ -1,12 +0,0 @@
----
-language: php
-php: 7.3
-addons:
-  apt:
-    packages:
-      - language-pack-fr
-install: composer install --no-progress
-script:
-  - composer check-platform-reqs
-  - composer lint
-  - composer test