Remove shift for private/protected/public.

It's not right to add shift after private/protected/public. The indention after private/protected/public is totally wrong formatted.

A normal ruby code should be this way:
```ruby
class Bla
  private
  def some_method
  end
end
```

But the now after running BeautifyRuby, it becomes this:
```ruby
class Bla
    private
      def some_method
      end
  end
```
Notice the heading space of the last line, it shouldn't be that way. When I use both BeautifyRuby and SublimeLinter, a warning will be raised to tell me there's a mismatch. So, there shouldn't be any shift after private/protected/public.