Tests: update ES1 client version check message

The name of the Python module changed over time and this now matches the
ES2 codebase behaviour of having the error message give you the exact
package to install including the version.

Author: acdha

test_haystack/elasticsearch_tests/__init__.py

@@ -17,8 +17,8 @@ def setup():
             raise ImportError
         from elasticsearch import Elasticsearch, ElasticsearchException
     except ImportError:
-        log.error("elasticsearch-py not installed.", exc_info=True)
-        raise unittest.SkipTest("elasticsearch-py not installed.")
+        log.error("'elasticsearch>=1.0.0,<2.0.0' not installed.", exc_info=True)
+        raise unittest.SkipTest("'elasticsearch>=1.0.0,<2.0.0' not installed.")
 
     es = Elasticsearch(settings.HAYSTACK_CONNECTIONS['elasticsearch']['URL'])
     try: