Fixes #7243 - CVV promotion out of sequence

This prevents content view versions from being promoted out of sequence.
promotion of content view versions can be forced to be promoted out of
sequence by passing the force param.
Can you add this test? I think this'll fail when it shouldn't.

```ruby
def test_promotoable_without_environments
  @cvv.expects(:environments).returns([]).at_least_once
  refute @cvv.promotable?(@dev)
end
```