Add comments, make comparison less strict

Using `assertIsInstance` should allow the intent of the test to be validated
without worrying about implementation issues like "does the mock library swap
out objects under the hood?"
Merge pull request #1538 from Ichimonji10/fix-test

Add comments, make comparison less strict
publish and promote function related to cv now return tas_id.

So now it waits for task to complete only if synchronous=True and
returns a task_id.
Merge pull request #1540 from kbidarkar/fix-taskid

publish and promote function related to cv now return tas_id.
Make test more strict

PR #1538 was made in an attempt to get PR #1536 to pass. That was a mistake, as
PR #1536 is broken.

Revert ea7c20d3983507b655cd8d6e9e77461a1b0d32da
Merge pull request #1539 from Ichimonji10/make-test-strict

Make test more strict
Added new `subscriptions` path for Organization.

Added a new `subscriptiond` path for `entities.Organization` to
facilitate tests that need to fetch what subscriptions are available to
a given organization. Also added tests.

Finally, I updated docstrings replacing ``:return:`` entries with the
correct value of ``:returns:`` and disabled some pylint directives.
Merge pull request #1536 from omaciel/add-subscriptions-api

Added new `subscriptions` path for Organization.
Add a test targeting BZ 1151220

Clients must submit a nested hash of attributes to certain API URLs.

For example, POSTing this data to the `/architectures` URL will succeed:

    {'name': 'foo'}

However, these operating system IDs will be silently ignored:

    {'name': 'foo', 'operatingsystem_ids': [1, 2, 3]}

A client can hack around this oddity by wrapping submitted data inside an extra
hash:

    {'architecture': {'name': 'foo', 'operatingsystem_ids': [1, 2, 3]}}

This extra hash should not be necessary. It makes the API harder to use, and
the extra hash is only required for some API calls.
Merge pull request #1541 from Ichimonji10/bz-1151220

Add a test targeting BZ 1151220
Added API tests for Docker images.

Added two new API tests for creating repositories that use Docker
content.

**NOTE**: To synchronize a ``Docker`` image, the ``name`` of your custom
  repository **must** match (case matters) the name of the Docker image.
  For example, the
  [WordPress](https://registry.hub.docker.com/_/wordpress/) image would
  require that your repository name be ``wordpress`` as it is displayed
  in its URL.
Merge pull request #1550 from omaciel/docker-api

Added API tests for Docker images.
Added UI tests for Docker images.

Added two new UI tests for creating repositories that use Docker
content. Please see #1550 for more information about naming conventions
for Docker repositories.

Both tests passed against today's nightly build.
Merge pull request #1551 from omaciel/docker-ui

Added UI tests for Docker images.