Merge pull request #267 from ESMValGroup/update_episode_10

Update episode 10 for using esmvaltool 2.7

Author: SarahAlidoost

.github/workflows/build-check-tutorial-site.yml

@@ -10,16 +10,9 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Setup Ruby
-      uses: ruby/setup-ruby@v1.64.1
+      uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 2.7
-    - name: Cache Ruby deps
-      uses: actions/cache@v2
-      with:
-        path: vendor/bundle
-        key: ruby-deps-${{ hashFiles('**/Gemfile.lock') }}
-        restore-keys: |
-          ruby-deps-
+        ruby-version: 3.1
     - name: Ruby deps
       run: gem install json kramdown jekyll bundler
     - name: Setup Python