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: I50229191f3a7bc42725f038f9b60eda724d4d4fc
(cherry picked from commit 09051f14f1b18de1ed674e30ad0d7d6956a8f0c3)