Remove Rust Audit (#37)

.github/workflows/rust-audit.yml

@@ -1,12 +0,0 @@
-name: Security audit
-on:
-  schedule:
-    - cron: '0 0 * * *'
-jobs:
-  audit:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v1
-      - uses: actions-rs/audit-check@v1
-        with:
-          token: ${{ secrets.GITHUB_TOKEN }}