build: add github actions workflow

Signed-off-by: Matthew Peveler <[email protected]>

Author: MasterOdin

.github/workflows/test.yml

@@ -0,0 +1,52 @@
+name: PHP Composer
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        php-version: ['7.1', '7.2', '7.3', '7.4']
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - uses: shivammathur/setup-php@v2
+      with:
+        php-version: ${{ matrix.php-version }}
+        tools: composer, pecl
+        coverage: pcov
+
+    - name: Validate composer.json and composer.lock
+      run: composer validate
+
+    - name: Cache Composer packages
+      id: composer-cache
+      uses: actions/cache@v2
+      with:
+        path: vendor
+        key: ${{ runner.os }}-${{ matrix.php-version }}-composer-${{ hashFiles('**/composer.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-${{ matrix.php-version }}-composer-
+          ${{ runner.os }}-composer-
+
+    - name: Install dependencies
+      if: steps.composer-cache.outputs.cache-hit != 'true'
+      run: composer install --prefer-dist --no-progress --no-suggest
+
+    - name: Setup pcov
+      run: vendor/bin/pcov clobber
+
+    - name: Lint
+      run: vendor/bin/phpcs --colors -p --standard=SubmittyStandard ./SubmittyStandard
+
+    - name: PHPUnit
+      run: vendor/bin/phpunit --filter SubmittyStandard
+
+    - uses: codecov/codecov-action@v1