Release 1.16.0: rotate cache version to flush stale entries

Minor-version bump from 1.15.x to 1.16.0. The solr_result_cache key is keyed on
the major.minor package version, so this invalidates all cached query results --
forcing fresh output that includes the linked dataset References, term labels,
Images carousel, and the other 1.15.x query-output fixes. No code change.

Author: Robbie1977

setup.py

@@ -3,7 +3,7 @@
 
 here = path.abspath(path.dirname(__file__))
 
-__version__ = "1.15.4"
+__version__ = "1.16.0"
 
 # Get the long description from the README file
 with open(path.join(here, 'README.md')) as f: