Issue #156 - Add a small RSpec "no parenthesis" example

The paragraph lists Situations. They're about when you should omit-parenthesis

It goes on to some Examples for each:
-attr_reader
-puts
-methods with no parameters

(There are more Examples I haven't listed; the ones for *include*-parenthesis Situations)

...This commit just adds one more Example. It's for a Situation that was mentioned in the paragraph but didn't have any Example: RSpec