Switch from Travis-CI to GitHub Actions (#66)

.github/workflows/ci.yml

+---
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php-version: ['5.6', '7.0', '7.1', '7.2', '7.3']
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up PHP ${{ matrix.php-version }}
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-version }}
+          ini-values: include_path=.:/usr/share/php:pear/usr/share/php
+      - name: Install dependencies
+        run: |
+          pear -v install -R pear -o Net_Socket
+      - name: Run tests
+        run: |
+          pear run-tests -d tests/

.travis.yml

-language: php
-branches:
-  only:
-    - "master"
-sudo: false
-php:
-  - 5.6
-  - 7.0
-  - 7.1
-  - 7.2
-  - 7.3
-install:
-  - pear channel-update pear.php.net
-  - pear list
-  - pear upgrade --force pear/pear
-  - pear list
-  - pear install package.xml
-  - pear list
-script:
-  - pear run-tests -d tests/