Fix docker/k8s builder script
Fix docker/k8s builder script

Removed bad `-f` option used in the script to build the
docker and K8s images. Also made sure the latest tag was
always added.

scalyr/scalyr-agent-2,scalyr/scalyr-agent-2,scalyr/scalyr-agent-2,imron/scalyr-agent-2,scalyr/scalyr-agent-2