chore: initial github ci

.github/workflows/ci.yml

@@ -0,0 +1,44 @@
+name: Rollbar-gem CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-16.04
+
+    strategy:
+      matrix:
+        ruby-version: [2.3.0, 2.3.8] #, 2.4.5, 2.5.3, 2.6.0]
+        gemfile:
+          - gemfiles/rails42.gemfile
+          - gemfiles/rails50.gemfile
+          #- gemfiles/rails51.gemfile
+          #- gemfiles/rails52.gemfile
+          #- gemfiles/rails60.gemfile
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Start Redis
+        uses: supercharge/[email protected]
+        with:
+          redis-version: 4
+
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+
+      - name: Bundle Install
+        run: |
+          bundle config path vendor/bundle
+          bundle config gemfile ${{ matrix.gemfile }}
+          bundle install --jobs 4 --retry 3
+
+      - name: Rspec
+        run: bundle exec rspec