💚 Explicit bundler version only

Author: pboling

.github/workflows/hoary.yml

@@ -36,7 +36,7 @@ jobs:
             appraisal: "ruby-2-2"
             exec_cmd: "rake spec"
             gemfile: "Appraisal.root"
-            rubygems: "2.7.11"
+            rubygems: default
             bundler: "1.17.3"
 
     steps: