[doc] Explain tests setup

README

@@ -24,3 +24,21 @@ entity in CubicWeb. This is handled by the `LinkResourceToDatasetHook` hook,
 which is abstract and should thus subclass by setting its `rtype` attribute.
 
 See ``test/data`` for a minimal example.
+
+
+Testing
+-------
+
+Testing this cube requires a running CKAN instance with a (dedicated)
+organization and a user with editors permission in the organization.
+Corresponding information are expected in the `test/ckanconfig.py` file.
+
+::
+
+    baseurl = '<url-of-ckan-instance>'
+    organization = '<organization-name>'
+    apikey  = '<api-key-of-user-with-editors-permissions-on-organization>'
+
+Note that, since CKAN does not expose an API function to purge datasets, we
+can only *delete* them in tests. So, one has to manually purge test datasets
+from the CKAN at `<baseurl>/ckan-admin/trash`.