Test cases: Additional test cases to be added to test_images.py and test_list_images.py

Following test cases are to be added to test_images.py in /tempest/tempest/tests

1. def test_create_image_with_exceed_metadata(self):
2. def test_create_image_without_metadata(self):
3. def test_create_image_multiple(self):
4. def test_create_image_with_tiny_flavor(self):
5. def test_create_image_with_sp_char(self):
6. def test_create_image_without_passing_name(self):
7. def test_delete_images_status_saving(self):

Following test cases are to be added to test_list_images.py in /tempest/tempest/tests

8. def test_get_image_details_for_image_in_saving_state(self):
9. def test_list_images_status_saving(self):
10. def test_list_images_status_deleted(self):
11. def test_list_images_by_server_url(self):
12. def test_list_images_by_nonexistant_server(self):