codegen: Allow connection to SSL servers

Currently the generator connects to a live engine using HTTP, without
SSL. This isn't the default configuration for a freshly installed
engine, so it makes generation a bit more complicated. This patch adds
support for connecting to a SSL protected server without verification.

Change-Id: I35ddfac416464876685b5e63b241db47e401626d
Signed-off-by: Juan Hernandez <juan.hernandez@redhat.com>