'Creates a test User if `self.CREATE_USER` is True.
Sets the password as self.user_password.'

def setUp(self):

    self.start_modulestore_isolation()
    self.addCleanup(self.end_modulestore_isolation)
    OverrideFieldData.provider_classes = None
    super(ModuleStoreTestCase, self).setUp()
    self.store = modulestore()
    uname = 'testuser'
    email = 'test+courses@edx.org'
    self.user_password = 'foo'
    if self.CREATE_USER:
        self.user = User.objects.create_user(uname, email, self.user_password)
        self.user.is_active = True
        self.user.is_staff = True
        self.user.save()
