Add sample database configuration file

To get new installations up and running quicker. It only contains a
'development' section for now.

Change-Id: I9038d110d2c9d5d660bec8c50fa24c92e781c5e6
Reviewed-on: https://gerrit.causes.com/22706
Tested-by: Aiden Scandella <aiden@causes.com>
Reviewed-by: Greg Hurrell <greg@causes.com>