ruby:3 for ui

Author: terrywbrady

mrt-services/ui/Dockerfile

@@ -5,8 +5,7 @@
 # See https://itnext.io/docker-rails-puma-nginx-postgres-999cd8866b18
 #   docker build -t cdluc3/mrt-dashboard .
 
-#FROM ruby:2.6.6
-FROM ruby:3.0
+FROM ruby:3
 RUN apt-get update -y -qq && apt-get install -y build-essential libpq-dev nodejs && apt-get -y upgrade
 
 # Set an environment variable where the Rails app is installed to inside of Docker image