Update a1-interface with nginx to support https

a1-interface is implemented with python flask
It does not support both http/https at the same time
This commit installs nginx in python image
nginx is serving http/https requests
All real traffic will be forwarded to python process
nginx is serving as a pure reverse-proxy

Issue-ID: NONRTRIC-218
Signed-off-by: ecaiyanlinux <martin.c.yan@est.tech>
Change-Id: I1edcd0d02023643feca042689283ef242d39e555