use GET method for count

as documented in the Elasticsearch API reference

Author: dmglab

elasticsearch/client/__init__.py

@@ -741,7 +741,7 @@ def count(self, index=None, doc_type=None, body=None, params=None):
  if doc_type and not index:
  index = '_all'
 
- _, data = self.transport.perform_request('POST', _make_path(index,
+ _, data = self.transport.perform_request('GET', _make_path(index,
  doc_type, '_count'), params=params, body=body)
  return data