Add cargo audit in travis ci
Add cargo audit in travis ci


Former-commit-id: 888d8376d4a61b2f1d1e78a1df7688da1a61dec4
alekseysidorov/exonum,exonum/exonum,alekseysidorov/exonum,alekseysidorov/exonum,exonum/exonum,exonum/exonum,alekseysidorov/exonum,exonum/exonum