Sort Rubocop directives in alphabetical order

[Bodacious]

This PR sorts the Rubocop Ruby configuration directives in alphabetical order.

I haven't changed/added/removed any of the rules.

I hope this doesn't seem pedantic, but I find it easier to read the rules and make sure there are no dupes when they are kept in order.

---

Code used to sort this file:

require "yaml"

filepath = "./.rubocop.ruby.yml"
hash = YAML.safe_load_file(filepath)
sorted_hash = Hash[hash.sort]
File.write(filepath, sorted_hash.to_yaml)

[Knack]

What if we do the same with .rubocop.rails.yml? We could do it even manually; it's small 😄

[Bodacious]

What if we do the same with .rubocop.rails.yml? We could do it even manually; it's small 😄

I was waiting to see how this PR was received before doing that. But I think it's a good idea :)

[Bodacious]

@Knack PR for the Rails file #194 :)