upgrade k8s vers, and add a script for future upgrades

.travis.yml

README.md

roles/docker/vars/ubuntu-16.04.yml

roles/download/defaults/main.yml

roles/kubernetes/node/defaults/main.yml

roles/uploads/defaults/main.yml

roles/uploads/tasks/main.yml

scripts/change_k8s_version.sh

tests/cloud_playbooks/create-aws.yml

tests/cloud_playbooks/create-gce.yml

tests/testcases/020_check-create-pod.yml

tests/testcases/030_check-network.yml