Update CLI host test_positive_create_1

Host creation now requires location and organization.

Add make_location CLI factory.
Merge pull request #1673 from elyezer/update-cli-test-host

Update CLI host test_positive_create_1
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`.

    $ 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

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