Nightly CI build for the Rails repo

Daily build with Ruby head

Failed in 8m 8s
:pipeline: rails-nightly-initial-pipeline
:docker: rubylang/ruby:master
Waited 10s
·
Ran in 4m 22s
:docker: rubylang/ruby:master-debug
Waited 7s
·
Ran in 7m 10s
Total Job Run Time: 12m 21s