Update CLI test_hammer_ping

Hammer ping requires username and password to work properly. Update the
test to grab the username and password from the properties file and them
when running the command.

Remove skip decorator as the test will run fine now.
Skip tests due to a new OS association bug with medium/partitiontable/template
Merge pull request #1674 from elyezer/update-cli-ping-test

Update test_hammer_ping
Merge pull request #1675 from sthirugn/templateclifix

Skip tests due to a new OS association bug with medium/partitiontable/template
Run tests that were skipped due to BZ 1162860

BZ 1162860 states that it is impossible to interact with a server using any user
other than the admin user. This is a false alarm, and the test errors occurred
due to an issue in robottelo itself. Drop references to BZ 1162860 and fix the
issue.

The `Field` class can store the "default" and "choices" instance attributes.
Unfortunately, `OneToOneField.get_value` and `OneToManyField.get_value` ignore
these attributes. Fix this issue by simplifying all `*Field.get_value` methods,
dropping `robottelo.orm._get_value`, and moving some extra value generation
logic in to `robottelo.orm.EntityCreateMixin.create_missing`. Drop some tests
to compensate for this change.

The test suite still behaves nicely. The four errors occurred because
manifest-related settings were not set, and the four failures are existing
issues.

    $ make test-foreman-api
    nosetests -c robottelo.properties tests/foreman/api
    Ran 773 tests in 3204.702s

    FAILED (SKIP=102, errors=4, failures=4)
    Makefile:41: recipe for target 'test-foreman-api' failed
    make: *** [test-foreman-api] Error 1
Cleaned up formatting of the cli base file
Also modified the cli test to account for a change in formatting.
Ran tests to ensure everything still worked correctly.

[jcallaha@dhcp129-121 robottelo]$ nosetests tests/foreman/cli/test_activationkey.py
.SSSSSS........................................................................
----------------------------------------------------------------------
Ran 79 tests in 1974.218s
Merge pull request #1676 from Ichimonji10/api-orm

Run tests that were skipped due to BZ 1162860
Merge pull request #1681 from JacobCallahan/clean-cli-base

Cleaned up formatting of the cli base file
Partially skip test due to BZ 1163494

Issuing an HTTP GET request for a non-existent repository triggers an HTTP 500
error with this error message:

    NoMethodError: undefined method `[]' for nil:NilClass

This only occurs if a repository with the given ID once existed. Fetching a
repository that has never existed will trigger an HTTP 404 as usual with a
message like this:

    Couldn't find Katello::Repository with id=600

Updated test results:

    $ nosetests tests/foreman/api/test_multiple_paths.py:DoubleCheckTestCase -m 'test_delete_and_get.*Repository'
    .
    ----------------------------------------------------------------------
    Ran 1 test in 11.153s

    OK
Merge pull request #1679 from Ichimonji10/bz-1163494

Partially skip test due to BZ 1163494
Fix Sphinx warnings

* Do not reference the non-existent modules `robottelo.factory` and
  `tests.robottelo.test_factory`.
* Do not reference the non-existent method `robottelo.factory.Factory.build`.
* Correctly demarcate a code block with `::`.
* Change a mistaken reference from `gen_missing` to `create_missing`.
Merge pull request #1691 from Ichimonji10/sphinx

Fix Sphinx warnings
Make API tests inherit from APITestCase

Group similar behaviour under a common class.
Drop old APITestCase related code

Drop old APITestCase helper functions.
Merge pull request #1694 from elyezer/api-testcase

Make API tests inherit from APITestCase
Merge pull request #1695 from elyezer/drop-old-code

Drop old APITestCase related code