ECOM-4214

Changed enrollment api to set enrollment atributes if the course is
credit course

ECOM-1719

ECOM-1273

The existing pattern of using `override_settings(MODULESTORE=...)` prevented
us from having more than one layer of subclassing in modulestore tests.

In a structure like:

    @override_settings(MODULESTORE=store_a)
    class BaseTestCase(ModuleStoreTestCase):
        def setUp(self):
            # use store

    @override_settings(MODULESTORE=store_b)
    class ChildTestCase(BaseTestCase):
        def setUp(self):
            # use store

In this case, the store actions performed in `BaseTestCase` on behalf of
`ChildTestCase` would still use `store_a`, even though the `ChildTestCase`
had specified to use `store_b`. This is because the `override_settings`
decorator would be the innermost wrapper around the `BaseTestCase.setUp` method,
no matter what `ChildTestCase` does.

To remedy this, we move the call to `override_settings` into the
`ModuleStoreTestCase.setUp` method, and use a cleanup to remove the override.
Subclasses can just defined the `MODULESTORE` class attribute to specify which
modulestore to use _for the entire `setUp` chain_.

[PLAT-419]

Consolidate PUT and POST on the RESTful Layer.

Change URLs for API

Test cleanup.

Adding a course details URL to the enrollment API.

Change student to user

Change to v1, remove feature flag from API URLs

Updating student to user in tests

Re-ordering redirect urls to be evaluated last.

Adding pagination and testing.

Adding Django REST settings for pagination.

Revert "Re-ordering redirect urls to be evaluated last."

This reverts commit 4c9502daa383e49b46f8abec5456c271e5e24ccb.

Re-ordering redirect urls to be evaluated last.

Conflicts:
	common/djangoapps/enrollment/urls.py

Revert "Adding Django REST settings for pagination."

This reverts commit 9f8a54c41f34caa24818c88f1e75ac59f6ce5259.

Conflicts:
	common/djangoapps/enrollment/urls.py

Revert "Adding pagination and testing."

This reverts commit 0b2d46262abb78f5ad170700205e7fd28b6af942.

Additional testing, logging, and error messages.

Also fixes failing Python unit tests

Updating tests for views

Last chunk of tests and pep8 cleanup

Code Review cleanup.

Additional CR comments

Changing serialization of suggested prices.