Fix: Danger with its own Gemfile, use actions/checkout@v2.

Author: dblock

.github/workflows/danger.yml

@@ -3,16 +3,21 @@ name: danger
 on: [pull_request]
 jobs:
   danger:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
         ruby-version: 2.6
         bundler-cache: true
     - name: Run Danger
+      env:
+        BUNDLE_GEMFILE: Gemfile.danger
       run: |
+        bundle install
         # the personal token is public, this is ok, base64 encode to avoid tripping Github
         TOKEN=$(echo -n NWY1ZmM5MzEyMzNlYWY4OTZiOGU3MmI3MWQ3Mzk0MzgxMWE4OGVmYwo= | base64 --decode)
-        DANGER_GITHUB_API_TOKEN=$TOKEN bundle exec danger --verbose 
+        DANGER_GITHUB_API_TOKEN=$TOKEN bundle exec danger --verbose

Gemfile

@@ -34,7 +34,3 @@ group :development, :test do
   gem 'vcr'
   gem 'webmock'
 end
-
-group :test do
-  gem 'slack-ruby-danger', '~> 0.1.0', require: false
-end

Gemfile.danger

@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+
+group :test do
+  gem 'danger-toc', '~> 0.2.0', require: false
+  gem 'slack-ruby-danger', '~> 0.2.0', require: false
+end