Update requirements for doc building

Remove unecessary requirements
Allow lfdocs-conf to initialise at latest version (0.7.7)
It now loads all centralized upper contraints from ONAP doc

Issue-ID: CPS-704
Signed-off-by: lukegleeson <luke.gleeson@est.tech>
Change-Id: I35e8e32b38229474e2a48ccaf126ab9aa760548f
2 files changed