[#64043152] Add vcloud-core gem to gemspec
[#64043152] Remove core files and tests
[#64043152] Remove fog files and tests
[#64043152] Remove vcloud-query executable

As it is now in bin. I haven't removed the documentation for now - we need to tidy this all up at some point but there's no harm in it being duplicated for now, as vcloud-query can still be used via vcloud-tools.
resolve merge conflicts
Merge pull request #116 from alphagov/use-core-gem

[#64043152] Use core gem