Update Docker build layer to go 1.11.13

[LucasRoesler]

Per the security announcement https://groups.google.com/forum/#!topic/golang-announce/65QixT3tcmg we should update the docker build layers to at least Go 1.11.13

Possible Solution

The builder layer in the Dockerfile should use golang:1.11

Related

Update Dockerfile and rebuild/release

https://github.com/openfaas/faas/issues/1291 https://github.com/openfaas/templates/issues/170 https://github.com/openfaas/faas-netes/issues/494 https://github.com/openfaas/nats-queue-worker/issues/66 https://github.com/openfaas-incubator/of-watchdog/issues/78 https://github.com/openfaas-incubator/faas-idler/issues/32 https://github.com/openfaas-incubator/golang-http-template/issues/28 https://github.com/openfaas-incubator/faas-federation/issues/4 https://github.com/openfaas-incubator/vcenter-connector/issues/27 https://github.com/openfaas-incubator/faas-memory/issues/3 https://github.com/openfaas-incubator/faas-rancher/issues/8

Only Rebuild

https://github.com/openfaas/faas-swarm/issues/56 https://github.com/openfaas-incubator/ingress-operator/issues/10 https://github.com/openfaas-incubator/openfaas-operator/issues/87

[alexellis]

https://github.com/openfaas-incubator/of-watchdog/releases/tag/0.6.0