add submodules, add protobuf-compiler

.github/workflows/ccpp.yml

@@ -9,6 +9,10 @@ jobs:
     
     steps:
     - uses: actions/checkout@v1
+    - name: deps
+      run: apt-get install protobuf-compiler
+    - name: submodules
+      run: git submodule update --init --recursive
     - name: make
       run: make
     - name: make check