insecure parameter to be removed for token based authentication

[Goutham Pratapa]

https://github.com/openstack/python-mistralclient/blob/master/mistralclient/auth/keystone.py#L95

here we are using insecure parameter for token-based authentication but ideally, the insecure parameter should not be used for token-based authentication

so it is suggested to remove that parameter.

Current-scenario:

mistral workbook-list --os-auth-token gAAAAABZwQwkeHNopwdDfE63FnZR37MLeyEMRc1d0WLDSOtEU86Y6rWS8kPV5gwiv52JsxictlIOnvXdwE_biwJP5u0csBkrZzvxyjQQ3BnCcNwEVWa0hd4tOTPxzNoyudAA29Kr-kZPbNpwrDAyjVLEdXG5s0ArqrWd7fa5XujcV1CVYIabKbE
ERROR (app) __init__() got an unexpected keyword argument 'insecure'

ideal scenario:

mistral workbook-list --os-auth-token gAAAAABZwQwkeHNopwdDfE63FnZR37MLeyEMRc1d0WLDSOtEU86Y6rWS8kPV5gwiv52JsxictlIOnvXdwE_biwJP5u0csBkrZzvxyjQQ3BnCcNwEVWa0hd4tOTPxzNoyudAA29Kr-kZPbNpwrDAyjVLEdXG5s0ArqrWd7fa5XujcV1CVYIabKbE
+------+------+------------+------------+
| Name | Tags | Created at | Updated at |
+------+------+------------+------------+
| | | | |
+------+------+------------+------------+

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/python-mistralclient 3.2.0 release.