Added namespace package example

Added namespace package example

Example shows how to implement namespace repa package. Namespace
packages are used to distribute extra functionality separately from
repa, but within repa namespace. External modules implemented this way
can be imported this way 'from repa import module'.

Change-Id: I79da170c4ba2562c7a022428c556ba06f2519e49
Signed-off-by: Ed Bartosh <eduard.bartosh@intel.com>
Reviewed-on: https://otctools.jf.intel.com/review/5837
Tested-by: OTC Tools Tester <ed.bartosh@linux.intel.com>