Update swagger UI to version 5.13.0
It seems that some bugs in the Swagger UI caused problems with
missing action input and output. This is fixed by simply updating
Swagger to a newer version.
Updated Swager UI from 5.11.8 to latest current version:
https://github.com/swagger-api/swagger-ui/releases/tag/v5.12.0
https://github.com/swagger-api/swagger-ui/releases/tag/v5.13.0
JIRA: NETCONF-1286
Change-Id: I47c2982f3d475a1523ec83683b83d6d3b2eea99e
Signed-off-by: Oleksandr Zharov <oleksandr.zharov@pantheon.tech>