To run the tests you should use runtests.py. For that to work you need to create
a config file at ~/.tryton-tests.cfg with the following sections::

   [branch-name-1]
   trytond = /path/to/trytond-1
   proteus = /path/to/proteus-1
   nereid = /path/to/nereid_app-1

   [branch-name-2]
   trytond = /path/to/trytond-2
   proteus = /path/to/proteus-2
   nereid = /path/to/nereid_app-1

Executing runtests.py will execute the tests against all branches. If you want
to run test against only one of them you can use the -b <branch> parameter.