Generate sitemap.xml to expose site to Google

Disabled initial_data.json to fix tests on CI server.
Extra line inserted in file to keep flake happy.
Made view test slightly stronger.
Add tests for sitemap class.
Fixed bug in settings.py that was loading wrong database engine for Sites.
Changed AllocationRequest for Python 2.7.
Test assertion for lists fixed.
Rebase to fix CI.
Changed frequency to monthly.
Collapse a log message. And agian.

Change-Id: I1d4fcd819b9792104abc8338ef1138ea99a788f1
Merge "Generate sitemap.xml to expose site to Google"