Add docstrings to pages.tests.test_handlers
Add docstring to pages.tests.test_models
Add docstrings to pages.tests.test_views
Add docstrings to redirects.tests.test_handlers
Add docstrings for redirects.tests.test_models
Refactor redirects.tests.test_views

* Split tests for permanent/temporary redirects from test for the
  redirect's target url
* Simplify integration test to focus on integration
* Remove essentially duplicate integration test
* Add docstrings