Change Ruby version.

Author: karlcloudy

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.3']
+        ruby-version: ['2.7']
 
     steps:
     - uses: actions/checkout@v2
@@ -30,7 +30,7 @@ jobs:
       uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby-version }}
-        bundler: 1.17.3
+        bundler: 2.1.4
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
     - name: Run tests
       run: bundle exec rspec spec