✨ Add Github actions CI

Author: simonrozsival

.github/workflows/main.yml

@@ -0,0 +1,29 @@
+name: build
+
+on: [push, pull_request]
+
+jobs:
+  test:
+
+    runs-on: ubuntu-20.04
+
+    strategy:
+      matrix:
+        ruby-version:
+          - 3.0.0
+          - 2.7.2
+          - 2.6.6
+          - 2.5.8
+          - 2.4.10
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up Ruby ${{ matrix.ruby-version }}
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+          bundler-cache: true
+
+      - name: Run tests
+        run: bundle exec rspec --format documentation