Documented reason for using south_pole_member in tests.
Added default account type of "Free" in config/applications.rb
Removed redundant logic for free account type in apps/views

A couple of pages were testing for an account type and displaying
"Free" if account type was nil. Now that we've ensured every account
has an account type, this is no longer necessary.
Updated tests to test for the default account type.

Tests used to check that the default account type was always "Free".
Now that we have a default account type as a config variable, the
tests test to see the default account type matches the value of that
variable.
Updated script/deploy-tasks.sh to include nil_account_type task.

We added a rake task to ensure all account have a Free account
type. This ensures the new nil_account_type rake task will be run
at deploy time.