elsticsearch - 'mapper_parsing_exception', u'failed to find type parsed [string] for [metric]'

Using elasticsearch to store benchmark result, fails when pkb tries to create the index:

2018-03-26 16:03:50,378 b5e669e5 MainThread WARNING PUT http://localhost:9200/perfkit/result/3ed2f574-e13b-4f43-9b11-92d198567be7/_create [status:400 request:0.075s]
Traceback (most recent call last):
File "./pkb.py", line 21, in
sys.exit(Main())
File "/home/ubuntu/PerfKitBenchmarker-1.13.0/perfkitbenchmarker/pkb.py", line 824, in Main
return RunBenchmarks()
File "/home/ubuntu/PerfKitBenchmarker-1.13.0/perfkitbenchmarker/pkb.py", line 750, in RunBenchmarks
collector.PublishSamples()
File "/home/ubuntu/PerfKitBenchmarker-1.13.0/perfkitbenchmarker/publisher.py", line 862, in PublishSamples
publisher.PublishSamples(self.samples)
File "/home/ubuntu/PerfKitBenchmarker-1.13.0/perfkitbenchmarker/publisher.py", line 631, in PublishSamples
id=sample['sample_uri'], body=json.dumps(sample))
File "/usr/local/lib/python2.7/dist-packages/elasticsearch/client/utils.py", line 76, in _wrapped
return func(*args, params=params, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/elasticsearch/client/__init__.py", line 279, in create
id, '_create'), params=params, body=body)
File "/usr/local/lib/python2.7/dist-packages/elasticsearch/transport.py", line 314, in perform_request
status, headers_response, data = connection.perform_request(method, url, params, body, headers=headers, ignore=ignore, timeout=timeout)
File "/usr/local/lib/python2.7/dist-packages/elasticsearch/connection/http_urllib3.py", line 180, in perform_request
self._raise_error(response.status, raw_data)
File "/usr/local/lib/python2.7/dist-packages/elasticsearch/connection/base.py", line 125, in _raise_error
raise HTTP_EXCEPTIONS.get(status_code, TransportError)(status_code, error_message, additional_info)
elasticsearch.exceptions.RequestError: TransportError(400, u'mapper_parsing_exception', u'failed to find type parsed [string] for [metric]')
---------------------------

ubuntu@benchmark:~/PerfKitBenchmarker-1.13.0$ pip list | grep elasticsearch
elasticsearch (6.2.0)
---------------------------

ubuntu@benchmark:~/PerfKitBenchmarker-1.13.0$ dpkg -l | grep elasticsearch
ii elasticsearch 6.2.0 all Elasticsearch is a distributed RESTful search engine built for the cloud. Reference documentation can be found at https://www.elastic.co/guide/en/elasticsearch/reference/current/index.html and the 'Elasticsearch: The Definitive Guide' book can be found at https://www.elastic.co/guide/en/elasticsearch/guide/current/index.html
----------------------------

ubuntu@benchmark:~/PerfKitBenchmarker-1.13.0$ sudo systemctl status elasticsearch.service
● elasticsearch.service - Elasticsearch
Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; disabled; vendor preset: enabled)
Active: active (running) since Mon 2018-03-26 15:50:20 UTC; 18min ago
Docs: http://www.elastic.co
Main PID: 24480 (java)
Tasks: 50
Memory: 1.3G
CPU: 23.826s
CGroup: /system.slice/elasticsearch.service
└─24480 /usr/bin/java -Xms1g -Xmx1g -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -XX:+AlwaysPreTouch -Xss1m -Djava.awt.headless=true -Dfil

Mar 26 15:50:20 benchmark systemd[1]: Started Elasticsearch.
---------------------------------

ubuntu@benchmark:~/PerfKitBenchmarker-1.13.0$ curl -XGET 'localhost:9200'
{
"name" : "temNuyr",
"cluster_name" : "LabsIT5",
"cluster_uuid" : "Nhz4m_e4Q5SNlYZbC_0bSg",
"version" : {
"number" : "6.2.0",
"build_hash" : "37cdac1",
"build_date" : "2018-02-01T17:31:12.527918Z",
"build_snapshot" : false,
"lucene_version" : "7.2.1",
"minimum_wire_compatibility_version" : "5.6.0",
"minimum_index_compatibility_version" : "5.0.0"
},
"tagline" : "You Know, for Search"
}
----------------------------

Not sure what to do getting this work. Even with older versions of elasticsearch its failing