Rspec mocks stub replacement

While I was using rspec3 as my basis I was getting:

Using `stub` from rspec-mocks' old `:should` syntax without explicitly enabling the syntax is deprecated. Use the new `:expect` syntax or explicitly enable `:should` instead. Called from /root/mutant/spec/unit/mutant/matcher/methods/singleton_spec.rb:43:in `block (2 levels) in <top (required)>'.

This pull request altered the syntax and eliminated that deprecation warning. 

Not sure it is correct, so willing to adjust. 
I'm okay to switch to rspec3 syntax. but I do not really like the alignment here. Can you fix the alignment to be like the original rspec2 syntax? Dot `.` in beginning of the continued two whitespace indented line?

Sorry I'm so nitpicky on all this details, but for me consistency is a huge value. And the more code I have to maintain the better its written in the a consistent style.