update workflow v3

well, that installation didn't work. let's try this.

.github/workflows/go.yml

@@ -20,7 +20,7 @@ jobs:
       run: mkdir -p /home/runner/go/bin
       
     - name: Install Go's dep dependency manager
-      run: curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
+      run: apt-get install -y dep
 
     - name: Check out code into the Go module directory
       uses: actions/checkout@v1