Fix nested examples

[straight-shoota]

Should fix these spec failures:

   Failures:

     1) Inflector #dasherize dasherizes correctly
        Failure/Error: it "dasherizes #{underscored} => #{dasherized}" do

          can't nest `it` or `pending`

        # spec/inflector_spec.cr:351

     2) Inflector #dasherize underscore_as_reverse_of_dasherize
        Failure/Error: it "dasherizes and underscores back to original #{underscored}" do

          can't nest `it` or `pending`

        # spec/inflector_spec.cr:359