Compile a minimal container image for podtracer

[acmenezes]

At this moment podtracer is running a big image based on the nikolaka/netshoot image. In order to have a minimal, ligthweight image for performance we need to:

• compile a minimal list of tools that can be run with podtracer (tcpdump, iperf, tcpreplay etc.)
• choose an image flavour that works better with Red Hat systems (ubi, fedora etc.)
• create a new Dockerfile for podtracer