Attempt 4: another recommended fix on github.

.github/workflows/main.yml

@@ -21,6 +21,7 @@ jobs:
         run: |
           sudo apt-get update --assume-yes
           sudo apt-get install --assume-yes --quiet gcc-multilib
+          sudo apt-get install --assume-yes --quiet ruby-dev
 
       # Checks out repository under $GITHUB_WORKSPACE
       - name: Checkout Latest Repo
@@ -34,7 +35,7 @@ jobs:
           sudo gem install bundler
           sudo gem install rspec
           sudo gem install rubocop -v 0.57.2
-          bundle install --no-cache 
+          bundle install 
 
       # Run Tests
       - name: Run All Unit Tests