'security' block is not loaded

[LuckyFenix]

Sphinx documentation generated from OpenAPI 3.0 doesn't contain information from security block. For example about required bearer token

[tchernobog]

Reference to standard: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#securitySchemeObject

[tchernobog]

Related to #61