quagga: use go1.11 on ubuntu:trusty
quagga: use go1.11 on ubuntu:trusty

avoid quagga update. It needs changes to the scenario_test code.

Signed-off-by: FUJITA Tomonori <93dac1fe9c4b2a3957982200319981492ad4976e@lab.ntt.co.jp>

osrg/dockerfiles