CI: clippy action

Author: surban

.github/workflows/rust-clippy.yml

@@ -32,6 +32,8 @@ jobs:
 
       - name: Checkout code
         uses: actions/checkout@v2
+        with:
+          submodules: recursive
 
       - name: Install Rust toolchain
         uses: actions-rs/toolchain@16499b5e05bf2e26879000db0c1d13f7e13fa3af #@v1