It'd be easier to make this a `POST` request, not a `GET` request - so this should probably be `treq.post` and not `treq.get`.  Both work (http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-request-body.html) but [treq has different arguments for get vs post](http://treq.readthedocs.org/en/latest/api.html).  The argument order here implies a post request.

Alternately, the data can be passed with the keyword `data`, because `get` expects headers as the second positional argument.

Attempting to run this against our ES instance, I get the following traceback (since post takes slightly different parameters than get):

```
Traceback (most recent call last):
  File "/mnt/hgfs/otter/otter/rest/decorators.py", line 164, in _
    return f(self, request, *args, **kwargs)
  File "/mnt/hgfs/otter/otter/rest/decorators.py", line 60, in _
    d = defer.maybeDeferred(f, self, request, *args, **kwargs)
  File "/opt/otter/current/lib/python2.7/site-packages/twisted/internet/defer.py", line 137, in maybeDeferred
    result = f(*args, **kw)
  File "/mnt/hgfs/otter/otter/rest/decorators.py", line 99, in _
    d = defer.maybeDeferred(f, self, request, *args, **kwargs)
--- <exception caught here> ---
  File "/opt/otter/current/lib/python2.7/site-packages/twisted/internet/defer.py", line 137, in maybeDeferred
    result = f(*args, **kw)
  File "/mnt/hgfs/otter/otter/rest/history.py", line 99, in history
    d = treq.get(append_segments(host, '_search'), json.dumps(data), log=self.log)
  File "/mnt/hgfs/otter/otter/util/logging_treq.py", line 78, in get
    return _log_request(treq.get, url, headers=headers, **kwargs)
  File "/mnt/hgfs/otter/otter/util/logging_treq.py", line 32, in _log_request
    d = treq_call(url=url, **kwargs)
  File "/opt/otter/current/lib/python2.7/site-packages/treq/api.py", line 20, in get
    return _client(**kwargs).get(url, headers=headers, **kwargs)
  File "/opt/otter/current/lib/python2.7/site-packages/treq/client.py", line 79, in get
    return self.request('GET', url, **kwargs)
  File "/opt/otter/current/lib/python2.7/site-packages/treq/client.py", line 129, in request
    method, url, headers=headers, bodyProducer=bodyProducer)
  File "/opt/otter/current/lib/python2.7/site-packages/twisted/web/client.py", line 1597, in request
    headers = headers.copy()
exceptions.AttributeError: 'str' object has no attribute 'copy'
```