Cleanup test_* indices on teardown.

README.md

@@ -60,3 +60,7 @@ variable `ELASTICSEARCH_DSN`. E.g.
 ### Testing
 
 Run: `pytest`
+
+Expects Elasticsearch for tests running on `localhost:9200` (can be override by
+environment variable `ELASTICSEARCH_DSN`). Tests creates random indices with
+prefix `test_` and deletes all indices matching `test_*` on teardown.

tests/conftest.py

@@ -10,7 +10,8 @@ def es():
     """Elasticsearch client."""
     es_dsn = os.environ.get('ELASTICSEARCH_DSN', 'http://localhost:9200')
     es_client = Elasticsearch(es_dsn)
-    return es_client
+    yield es_client
+    es_client.indices.delete('test_*')
 
 
 @pytest.fixture