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: I2a790875a7dfaa2d91ff78a695b314c69bf7938d
(cherry picked from commit 595baf6c989d854c8d461405098a9f35bd743067)