refactoring: move BeleniosElectionTestBase to its own file, remove unused imports

tests/settings.py

 #!/usr/bin/python
-# -*- coding: utf-8 -*
+# coding: utf-8
 
 from os.path import abspath, dirname
 

tests/test_scenario_2.py

 #!/usr/bin/python
-# -*- coding: utf-8 -*
+# coding: utf-8
 import unittest
-import time
-import string
 import random
 import os
-import shutil
 import subprocess
 import re
 import sys
 from uuid import uuid4
 from distutils.util import strtobool
-from selenium import webdriver
-from selenium.webdriver.common.keys import Keys
-from selenium.webdriver.common.alert import Alert
 from selenium.common.exceptions import UnexpectedAlertPresentException
 from util.fake_sent_emails_manager import FakeSentEmailsManager
-from util.selenium_tools import wait_for_element_exists, wait_for_elements_exist, wait_for_element_exists_and_contains_expected_text, wait_for_element_exists_and_has_non_empty_content, wait_for_an_element_with_partial_link_text_exists, set_element_attribute, verify_element_label, wait_for_element_exists_and_has_non_empty_attribute
-from util.election_testing import console_log, random_email_addresses_generator, populate_credential_and_password_for_voters_from_sent_emails, populate_random_votes_for_voters, repopulate_vote_confirmations_for_voters_from_sent_emails, remove_database_folder, wait_a_bit, build_css_selector_to_find_buttons_in_page_content_by_value, find_button_in_page_content_by_value, find_buttons_in_page_content_by_value, initialize_server, initialize_browser, election_page_url_to_election_id, verify_election_consistency, create_election_data_snapshot, delete_election_data_snapshot, log_in_as_administrator, log_out, administrator_starts_creation_of_election, administrator_edits_election_questions, administrator_sets_election_voters, administrator_validates_creation_of_election
-from test_scenario_1 import BeleniosElectionTestBase
+from util.selenium_tools import wait_for_element_exists, wait_for_elements_exist, wait_for_element_exists_and_contains_expected_text, wait_for_element_exists_and_has_non_empty_content, wait_for_an_element_with_partial_link_text_exists, set_element_attribute, wait_for_element_exists_and_has_non_empty_attribute
+from util.election_testing import console_log, random_email_addresses_generator, remove_database_folder, wait_a_bit, build_css_selector_to_find_buttons_in_page_content_by_value, initialize_server, initialize_browser, election_page_url_to_election_id, verify_election_consistency, create_election_data_snapshot, delete_election_data_snapshot, log_in_as_administrator, log_out, administrator_starts_creation_of_election, administrator_edits_election_questions, administrator_sets_election_voters, administrator_validates_creation_of_election
+from util.election_test_base import BeleniosElectionTestBase
 import settings
 
 

tests/util/fake_sent_emails_manager.py

 #!/usr/bin/python
-# -*- coding: utf-8 -*
+# coding: utf-8
 import re
 import subprocess
 

tests/util/selenium_tools.py

 #!/usr/bin/python
-# -*- coding: utf-8 -*
+# coding: utf-8
 from selenium.webdriver.support.ui import WebDriverWait
 from selenium.webdriver.common.by import By
 from selenium.webdriver.support import expected_conditions as EC