Style clean-up and small refactors

Hi there,

This is mostly a cosmetic PR and small refactoring to clean up styles according to the [Ruby Style Guide](https://github.com/bbatsov/ruby-style-guide). I find this much easier to read that what Hound suggests (single quoted strings, for example). Feedback welcome.
This is hard to read, it was kinda hard to read originally TBH, but I think it's harder. I would extract the block to it's own line and variable assignemend, then do `unless has_pgbackups` or something like that. Thoughts?