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: I2719f18c097e62252eac3f491cafb1269335cfcd
(cherry picked from commit b0f7504f13f73b8ea6e5f331fb3925a13a5be684)