Merge branch 'dev' into 'master'

Check if collection has predecessor

See merge request !22

ckanext/odsh/templates/package/read.html

@@ -5,7 +5,7 @@
 {% set collection_title = collection['title'] if collection else None %}
 {% set collection_url = collection['url'] if collection else None %}
 {% set successor_url = collection['successor']['url'] if collection and 'successor' in collection else None %}
-{% set predecessor_url = collection['predecessor']['url'] if collection else None %}
+{% set predecessor_url = collection['predecessor']['url'] if collection and 'predecessor' else None %}
 {% set latest_collection_member = collection['persistent_link_last_member'] if collection else None %}
 {% set stars = h.odsh_openness_score_dataset_html(pkg) %}