Merge pull request #44 from nsmith5/bugfix/tls1.3

Bump resource class image version to support TLS 1.3

Author: ryanwohara

.circleci/config.yml

@@ -1,7 +1,8 @@
 version: 2
 
 resource_job_defaults: &resource_job_defaults
-  docker:  [{image: 'circleci/ruby:2.4.1'}]
+  docker:
+    - image: 'cimg/base:2021.02-20.04'
   steps:
     - run:
         name: verify required Environment Variables