Double quote strings that contain single quotes only (retry) #336
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Original pull request: #325
@knugie Your changes was different behavior with bundler behavior: https://github.com/bundler/bundler/blob/master/lib/bundler/yaml_serializer.rb#L8
There is no time to coordinate this specification for Ruby 2.5.0. I try to this next year(Ruby 2.6 and psych 3.1.0)