Add workflow for testing

.github/workflows/pry-diff-routes.yml

@@ -0,0 +1,26 @@
+name: pry-diff-routes
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  test:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        ruby: [2.4.9, 2.5.7, 2.6.5, 2.7.0, ruby-head, jruby-9.2.11.0, jruby-head, truffleruby-20.0.0, rbx-4.14]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+    - name: Build and test with Rake
+      run: |
+        gem install bundler
+        bundle install --jobs 4 --retry 3
+        bundle exec rake