Improve Swagger UI Update Process

Improve Swagger UI Update Process

Our custom code is now separated in:
styles.css, swagger-initializer.js, logo_small.png
and configuration.js. Everything controlled from index.html.

Everything from swagger UI distro is now placed in swagger-ui directory
without any modification.

This helps us make the process to update to latest swagger UI
distribution easier.

All we need is to replace the content of swagger-ui directory.

JIRA: NETCONF-1302
Change-Id: I389b52026e832f3b21834546ec4d4362cbd518dd
Signed-off-by: Anton Okhrimenko <Anton.Okhrimenko@pantheon.tech>
Signed-off-by: Ivan Hrasko <ivan.hrasko@pantheon.tech>