Adding basic test for User creation via API.

The following changes add a basic test for the creation of Users via the
API layer. More tests will be added in the near future.
Handling feedback from Jeremy.
Using ``orm.StringFiend`` for data-driven args.

Replacing the explicit use of ``FauxFactory`` by ``orm.StringField`` now
that we can specify the string type.
Updated User entity to use explicit string types.

Now that we can control what type of data is generated for
``orm.StringType``, I have updated the ``User`` entity to explicitly
require all string types provided by ``FauxFactory`` with the exception
of ``utf8`` strings for the ``login`` field, as they make ``Foreman`` to
barf and return a 500.
Fix ``orm.StringField`` usage and assertion.

Updated my call to ``orm.StringField`` to use the correct syntax as well
as perform the ``get_value()`` method inside the decorator. Also,
removed the ``password`` field from my assertion block since the ``GET``
method does not return it.
Merge pull request #1080 from omaciel/user-api-v2-test

Adding basic test for User creation via API.