When trying to execute the fullstack tests, I was a little bit lost in
the documentation.
This change is a proposal to refactor this a little bit so the only
source of truth is the doc/source/contributor/testing/fullstack.rst
file.
Change-Id: Ibaf2ab9a227d71d18adf027d2ae509168c1e26da
Signed-off-by: Arnaud Morin <arnaud.morin@ovhcloud.com>