Add 'cargo audit' step to standard workflow

Author: tyler

.github/workflows/rust.yml

@@ -17,3 +17,14 @@ jobs:
       run: cargo build --verbose
     - name: Run tests
       run: cargo test --verbose
+
+  audit:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install Cargo Audit
+      run: cargo install cargo-audit
+    - name: Audit
+      run: cargo audit

README.md

@@ -1,4 +1,4 @@
-![Rust](https://github.com/fastly/userfaultfd-rs/workflows/Rust/badge.svg)
+![Build](https://github.com/fastly/userfaultfd-rs/workflows/Rust/badge.svg)
 
 # userfaultfd-rs
 Rust bindings for Linux's userfaultfd functionality.