Use absolute name of Vcloud::Core in unit tests

In preperation for removing the outer `module` block on these tests and
using an outer `describe` on the class that we're testing.
Absolute refs to VmOrch and VappOrch in units test

In preperation for removing the outer `module` block on these tests and
using an outer `describe` on the class that we're testing.

Some of these could be replaced by defining `subject{}` to setup a class
object with the appropriate arguments.
Remove outer module block from unit tests

So that our tests aren't extending and implicitly namespaced into the
`Vcloud` module. This will make it more obvious where we're crossing the
boundaries of different projects. It will also instantiate the class given
(without any args) and make it available as `subject` which may allow us to
DRY up some of our tests.
Use subject in Launcher::Launch unit tests

The outer describe block sets this up for us. Since we don't need to pass
any arguments to the class itself (only the methods) and the methods are
public (unlike VappOrchestrator).
Merge pull request #29 from alphagov/70508876-namespace_tests

[Fixes #70508876] Namespacing for unit tests