Try out Github actions

.github/workflows/ruby.yml

@@ -0,0 +1,36 @@
+name: Ruby
+
+on: [push]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Ruby 2.6
+      uses: actions/setup-ruby@v1
+      with:
+        ruby-version: 2.6.x
+    - name: Build and test with Rake
+      run: |
+        gem install bundler -v 1.16
+        bundle install --jobs 4 --retry 3
+        bundle exec rubocop
+
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby_version: [2.4.x, 2.5.x, 2.6.x]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Ruby ${{ matrix.ruby_version }}
+      uses: actions/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby_version }}
+    - name: Build and test with Rake
+      run: |
+        gem install bundler -v 1.16
+        bundle install --jobs 4 --retry 3
+        bundle exec rspec