SeleniumServer: Chrome 91 and Firefox 78

See merge request !1003
4 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed SlapOS.Eggs.UnitTest-Master.Python2

00:31:22

passed SlapOS.Eggs.UnitTest-Master.Python3

00:18:15

passed SlapOS.SlapRunner.ResilienceTest-Master

00:22:44

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

00:24:38