Update apt before install

.github/workflows/main.yml

@@ -21,7 +21,8 @@ jobs:
     steps:
     # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
     - uses: actions/checkout@v2
-
+    - name: Update apt-get
+      run: sudo apt-get update
     - name: Install deps
       run: sudo apt-get install coreutils quilt parted qemu-user-static debootstrap zerofree zip dosfstools bsdtar libcap2-bin grep rsync xz-utils file git curl bc
     # Runs a single command using the runners shell