Added integration tests

[Marketionist]

This pull request adds integration tests

Details:

• log in test
• page creation test
• group creation test

Also:

• test_settings.py update for test server to run properly

Important This branch should be merged with https://github.com/aldryn/aldryn-people/pull/87

[Marketionist]

The tests are failing only for one configuration - TOXENV=py27-dj18-cms31 (see https://travis-ci.org/aldryn/aldryn-people/builds/73433262 and "Bad Gateway" problem with the server - http://saucelabs.com/jobs/83cdfae2a50d40918a78d165779a455b).

Here is the possible cause of the issue: maybe the issue is coming from aldryn-people or one of the other dependencies - basically one method is causing self.stderr getting called in a wrong way (see also https://code.djangoproject.com/ticket/24477#comment:1) /cc @mkoistinen @jmelett @FinalAngel

[FinalAngel]

LGTM