Fixes #174 - loads ajax request only on /organizations

This is a patch for #174, but it's not perfect. The ajax request
happens twice when going from the homepage to the search results page
(see #175).
Simplifies organization routes

Organization routes was mapped to a resource, which expects a database
entity, which no longer exists. Therefore, the route has been
simplified to two get requests.
Removes reference to created_at

created_at field was used as a fallback for when updated_at field was
not present, but the updated_at field should always be present, even
when the record is first created (in which case it has the same value
as created_at).