vault-ruby: vault-ruby cannot write secrets to vault server, version >=0.10.0

Writing a secret with the CLI:

root@bootstrap-ubuntu-1604:~# vault version
Vault v0.10.0 ('5dd7f25f5c4b541f2da62d70075b6f82771a650d')
root@bootstrap-ubuntu-1604:~# vault kv put secret/bacon "delicions=true,cooktime=11"
Key              Value
---              -----
created_time     2018-08-07T20:42:02.333492408Z
deletion_time    n/a
destroyed        false
version          1

Writing a secret with vault-ruby:

[1] pry(main)> require 'vault'
[2] pry(main)> client = Vault::Client.new(address: 'http://127.0.0.1:8200', token: File.read('/root/.vault-token'))
[3] pry(main)> client.logical.write("secret/bacon", delicious: true, cooktime: "11")
Vault::HTTPClientError: The Vault server at `http://127.0.0.1:8200' responded with a 404.
Any additional information the server supplied is shown below:

  * {"request_id":"7e8e4d50-4972-2129-4dc4-4e0c7ef37db9","lease_id":"","renewable":false,"lease_duration":0,"data":null,"wrap_info":null,"warnings":["Invalid path for a versioned K/V secrets engine. See the API docs for the appropriate API endpoints to use. If using the Vault CLI, use 'vault kv put' for this operation."],"auth":null}

The last version of vault that still works is 0.9.6.