Convert and delete some old API tests

Remove the following modules:

1. `test_computeresource`
2. `test_configtemplate`
3. `test_domain`
4. `test_environments`

The first three contained no working tests and no interesting test stubs. The
existing test stubs were for goals such as creating or deleting an entity. Given
that all four relevant entities are already tested in module
`test_multiple_paths`, there is no value to the stubs.

The fourth module contains tests for creating environments with valid and
invalid names. Port these tests to module `test_environment_v2`.

Remove outdated module references from the API documentation.
Relevant comment:

> In the context of this test, an "invalid name" is one that it either too
> long or contains illegal characters. The API returns this error message
> when an illegal character is submitted:
>
>     Name is alphanumeric and cannot contain space