Setup GitHub workflows

Author: Mattia Roccoberton

.github/workflows/specs.yml

@@ -0,0 +1,26 @@
+name: Specs
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        ruby: ['2.5', '2.6', '2.7']
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
+      - name: Run tests
+        run: bundle exec rake