DevOps: Updating Ruby version

Part 1 - Test application level changes locally

In local development:

Install the desired Ruby version with your Ruby version manager (rvm, rbenv, etc.)
Update the ruby version at the top of the Gemfile and run bundle install . Resolve any clashing dependencies. Confirm the Ruby version has changed in .ruby-version and Gemfile.lock
Update the Ruby version in CI config file
Run the tests to confirm there are no other breaking changes

Create a PR adding a Dockerfile for the new Ruby version in agilesix/Dockerfiles and get review
Follow instructions (DevOps: Update VA AWS ECR image ) to build new and tag Ruby image and push to VAEC ECR.

On the ec2 server, change the Dockerfile image name and the Gemfile Ruby version:

cd diffusion-marketplace
vi Dockerfile 
vi Gemfile

sudo docker-compose build app 
sudo docker system prune -f

Restart the app:

./scripts/start_appcontainer.sh

Update the PR with the following and merge into master after code review:

Update the image version in the Dockerfile
Change Ruby version in README
Update image version in Jenkins deploy scripts - both on the server and in the scripts/jenkins folder

Deploy to each environment and test using the normal deploy workflow.