Correct changelog version for initial Gem release

The initial release as a Gem used version 0.0.1, not 0.0.2.
[#69915642] Bump vCloud Core version to 0.0.12

Bump vCloud Core to version 0.0.12, which fixes an issue where tasks
that would show a progress bar fall over which this error message:

```
undefined method `<' for nil:NilClass
```
Merge pull request #7 from alphagov/bump-vcloud-core

[#69915642] Bump vCloud Core version to 0.0.12