nhsbsa 0.1.0

• Initial release: a low-level client for the NHS Business Services Authority (NHSBSA) Open Data Portal, a CKAN data catalogue.
• Dataset endpoints: nhsbsa_package_list(), nhsbsa_package_show() and nhsbsa_package_search().
• Resource endpoints and file download: nhsbsa_resource_show(), nhsbsa_list_resources() and nhsbsa_download_resource().
• Datastore row queries: nhsbsa_datastore_search() and nhsbsa_datastore_search_sql().
• Catalogue listings: nhsbsa_organization_list(), nhsbsa_group_list() and nhsbsa_tag_list().
• nhsbsa_package_show(), nhsbsa_resource_show() and nhsbsa_package_search() return classed lists with tidy print() methods, and tibble::as_tibble() methods that turn a dataset into its resources and a search into one row per dataset.