Use security plugin in CI

[kaituo]

Is your feature request related to a problem? Please describe.
We don't have a way to enable security plugin while still doing CI. As per my understanding it needs updates in ESRestTestCase class, cause they have provision to enable https calls but it needs to be set in the code.

Describe the solution you'd like
We may have a subclass of ESRestTestCase and override some of their methods. See https://github.com/opendistro-for-elasticsearch/sql/pull/473/files and opendistro-for-elasticsearch/alerting#213

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.