Add code wars (8) - alternating case
user
```ruby
# http://www.codewars.com/kata/56efc695740d30f963000557/
# --- iteration 1 ---
class String
  def to_alternating_case
    self.swapcase
  end
end

# --- iteration 2 ---
class String
  def to_alternating_case
    swapcase
  end
end
```
assistant