'Log in a user.
You must send all required form fields with the request.
You can optionally send an `analytics` param with a JSON-encoded
object with additional info to include in the login analytics event.
Currently, the only supported field is "enroll_course_id" to indicate
that the user logged in while enrolling in a particular course.
Arguments:
request (HttpRequest)
Returns:
HttpResponse: 200 on success
HttpResponse: 400 if the request is not valid.
HttpResponse: 403 if authentication failed.
403 with content "third-party-auth" if the user
has successfully authenticated with a third party provider
but does not have a linked account.
HttpResponse: 302 if redirecting to another page.
Example Usage:
POST /user_api/v1/login_session
with POST params `email`, `password`, and `remember`.
200 OK'

@method_decorator(require_post_params(['email', 'password']))
@method_decorator(csrf_protect)
def post(self, request):

    from student.views import login_user
    return shim_student_view(login_user, check_logged_in=True)(request)
