enable datastore and datapusher.

add steps to install the extensions from below links:

* [Setting up the DataStore.](https://docs.ckan.org/en/2.8/maintaining/datastore.html#setting-up-the-datastore)
* [Datapusher: Production installation and Setup](https://docs.ckan.org/projects/datapusher/en/latest/deployment.html)

add plugins:

    ckan.plugins = ...... datastore datapusher