Publish artifacts to S3 repository

Publish artifacts to S3 repository

It simplifies Jenkins or Gitlab jobs by automatically publishing all
artifacts via the framework.

It leverages on Amazon Web Services (AWS) SDK [1] which supports the
current cases (OPNFV, Xtesting Ansible role [2], etc.).

[1] https://boto3.amazonaws.com/v1/documentation/api/latest/index.html?id=docs_gateway
[2] https://github.com/collivier/ansible-role-xtesting

Change-Id: I66e380c4da29fb0f973472a2c59ae0ea3c44fcfd
Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>