Setup Ruby for deployment (#38)

Author: hamermike

.github/workflows/deploy.yml

@@ -14,6 +14,11 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v2
 
+    - name: Setup Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: '3.0'
+
     - name: Install Packages
       run: bundle install