🔧 rubygems default for ruby v2.2

Author: pboling

.github/workflows/hoary.yml

@@ -35,7 +35,8 @@ jobs:
             appraisal: "ruby-2-2"
             exec_cmd: "rake spec"
             gemfile: "Appraisal.hoary"
-            rubygems: "2.7.11"
+            # rubygems: "2.4.5.5"
+            rubygems: default
             bundler: "1.17.3"
 
     steps: