Check udeps (#1535)

.github/workflows/ci.yml

@@ -190,6 +190,23 @@ jobs:
       run: |
         cargo deny check bans
 
+  udeps:
+    name: udeps
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: Install Rust
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: nightly
+        override: true
+        
+    - name: cargo-udeps
+      run: |
+        cargo install --locked cargo-udeps
+        cargo +nightly udeps --all-targets
+
+
   sec:
     name: Security audit
     runs-on: ubuntu-latest