Test bundle exec too

Author: eregon

.github/workflows/test.yml

@@ -39,10 +39,9 @@ jobs:
       run: ruby -ropen-uri -e 'puts open(%{https://rubygems.org/}) { |f| f.read(1024) }'
     - name: C extension test
       run: gem install json:2.2.0 --no-document
-    - name: Bundler version
-      run: bundle --version
-    - name: Bundler test
-      run: bundle install
+    - run: bundle --version
+    - run: bundle install
+    - run: bundle exec rake --version
 
   lint:
     runs-on: ubuntu-latest

Gemfile

@@ -1,5 +1,6 @@
 # Used for testing
 source 'https://rubygems.org'
 
+gem "rake"
 gem "path"
 gem "json", "2.2.0"