add setup rust toolchain

Author: ali-behjati

.github/workflows/check-build.yml

@@ -10,6 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
+    - uses: actions-rust-lang/setup-rust-toolchain@v1
     - name: Install protoc
       uses: arduino/setup-protoc@v3
       with: