Run Kube2msb as a non-root user

https://wiki.onap.org/display/DW/Best+Practices

• The Docker and Kubernetes engines may run as root until such time as the products support non-root execution.
• Applications may run as root within a container.
• The process ID of a container must not run as the root ID with the exception of containers supporting ONAP features that require the container to run as the root ID.
• Containers may run with root privileges.
• Project containers that run as the root ID must document this in the release notes along with the functionality that requires the container to run as the root ID.