Update all workflows to use Ruby 2.7

Author: nateranson

.github/workflows/create-release-marketing.yml

@@ -343,7 +343,7 @@ jobs:
           unzip zip/mailchimp-marketing-ruby.zip -d swagger-out/marketing-ruby
 
       - name: Set up Ruby 2.7
-        uses: actions/setup-ruby@v1
+        uses: ruby/setup-ruby@v1
         with:
           ruby-version: '2.7'
 
@@ -528,10 +528,10 @@ jobs:
           path: .cache
           key: cache-dir
 
-      - name: Install Ruby 2.6.x
-        uses: actions/setup-ruby@v1
+      - name: Install Ruby 2.7
+        uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 2.6.x
+          ruby-version: 2.7
 
       - name: Prepare Build & Publishing Tools
         run: |

.github/workflows/create-release-transactional.yml

@@ -336,10 +336,10 @@ jobs:
           mkdir -p swagger-out/transactional-ruby
           unzip zip/mailchimp-transactional-ruby.zip -d swagger-out/transactional-ruby
 
-      - name: Set up Ruby 2.6
+      - name: Set up Ruby 2.7
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '2.6'
+          ruby-version: '2.7'
 
       - name: Install client dependencies
         run: gem install rspec
@@ -517,7 +517,7 @@ jobs:
       - name: Install Ruby 2.6.x
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 2.6.10
+          ruby-version: 2.7
 
       - name: Prepare Build & Publishing Tools
         run: |

.github/workflows/test-marketing.yml

@@ -118,10 +118,9 @@ jobs:
           unzip zip/mailchimp-marketing-ruby.zip -d swagger-out/marketing-ruby
 
       - name: Setup Ruby
-        uses: ruby/setup-ruby@v1.237.0
+        uses: ruby/setup-ruby@v1
         with:
           ruby-version: '2.7'
-          bundler-cache: false
 
       - name: Install client dependencies
         run: gem install rspec