Leverage upper-constraints files to pin all dependencies

Leverage upper-constraints files to pin all dependencies

It leverages the latest change from lfdocs-conf and the
upper-constraints.txt now centralized in ONAP docs.
In a long run, upperconstraints.os.txt should be removed once ONAP
is synced with OpenStack.

It removes tox and setuptools from requirements as nothing depends on them
(most requirements should be removed except lfdocsconf)

Issue-ID: DOC-765

Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
Change-Id: I63da3905aa77d561b28aedc8d9b69e535852206d
(cherry picked from commit 22af228260d82a944350e2e5073cefb6562f59cc [formerly 6f7fa79eaed75440f53fc0b061a7d2a0cd1a1305])

Former-commit-id: 4620cb261d8f137d1c15a7bf90246f010310d8e0