Prevents the following deprecation warning:
[DEPRECATED] The `--path` flag is deprecated because it relies on
being remembered across bundler invocations, which bundler will no
longer do in future versions. Instead please use `bundle config set
path 'vendor/bundle'`, and stop using this flag.
Was missing the checksum which would cause Ruby to be downloaded and
rebuilt each time.
The Docker image has been updated to use an unspecified version to
reduce version maintenance.
The `CI_RUBY_VERSION` environment variable was introduced to be
dynamically set based on value in the `.ruby-version` for improved
maintainability.
