SublimeText/RSpec — pull request #42 by driket (2014-04-30 17:07:06+00:00)
Title: Use of single quote for static text in Ruby

'it', 'describe' and 'context' blocs are generally static text strings.
Since they don't need string interpolations and/or symbols, they shouldn't use double quoted strings.

I tend to use this guide as a reference, because most of Ruby linters / static code analyzers follow it (Rubocop, Puppet Linter, Cane) : https://github.com/bbatsov/ruby-style-guide

Unfortunately there are two different opinions about usage of single/double quoted strings.
None of them is "the officially recognized one" as far as I know.