travis: attempt to invoke Coverity scan after each build

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10381 ddefafc4-47db-0310-ae44-fa13212b10f2
travis: attempt to invoke Coverity scan after each build (perms)

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10382 ddefafc4-47db-0310-ae44-fa13212b10f2