Add tftpc integration tests

.github/workflows/integration.yml

@@ -20,6 +20,6 @@ jobs:
           sudo apt-get update
           sudo apt-get install atftp
       - name: Build
-        run: cargo build --verbose
+        run: cargo build --features client --verbose
       - name: Run tests
         run: cargo test --test integration_test --features integration --verbose -- --test-threads 1