While adding the current user is a useful default behaviour for
creating new images it is not appropriate for Travis which already has
a default user.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170725133425.436-2-alex.bennee@linaro.org>
Signed-off-by: Fam Zheng <famz@redhat.com>