Fix github action and install gcc

Author: jericks

.github/workflows/build.yml

@@ -9,6 +9,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+      - name: install dependencies
+        run: |
+          sudo apt update
+          sudo apt install gcc-10 g++-10
+        shell: bash
       - name: Set up JDK 1.8
         uses: actions/setup-java@v1
         with: