travis: build contrib/cgi/
travis: build contrib/cgi/

Enable building the stand-alone CGI interface in Travis CI.

Signed-off-by: Bastian Stender <591dbcb2d48f405f0cb405f5aa6519451f40ad30@pengutronix.de>

rauc/rauc,rauc/rauc,ejoerns/rauc,jluebbe/rauc,rauc/rauc,ejoerns/rauc,jluebbe/rauc,ejoerns/rauc,jluebbe/rauc