CLOVER-43: Initial commit for Clovisor

CLOVER-43: Initial commit for Clovisor

Part of Clover's initial task (during project proposal) is to explore
cloud native network tracing tools. Clover the project proposes
Clovisor as a way for Clover to use the IOvisor
(https://www.iovisor.org/) to perform network tracing. This is the first
commit of this module

Please note that the BPF code used in this commit were only tested with
Linux kernel 4.14+ --- hence, if ubuntu is used, and one prefers LTS,
the requirement is 18.04+

A different patch will track the redis and k8s API server watcher code

Also, a design doc will be added in the future (TBD)

Signed-off-by: Stephen Wong <stephen.kf.wong@gmail.com>
Change-Id: I30d9f9d474b8703097c470d39628e86bc788f9b6