Add cargo audit to CI (#1192)

.github/workflows/test-suite.yml

@@ -92,3 +92,10 @@ jobs:
    - uses: actions/checkout@v1
    - name: Validate state_processing feature arbitrary-fuzz
      run:  make arbitrary-fuzz
+  cargo-audit:
+   runs-on: ubuntu-latest
+   needs: cargo-fmt
+   steps:
+   - uses: actions/checkout@v1
+   - name: Run cargo audit to identify known security vulnerabilities reported to the RustSec Advisory Database
+     run:  make audit