Update to stable versions of GitHub Actions

Author: belak

.github/workflows/ci.yml

@@ -12,17 +12,20 @@ jobs:
 
     steps:
     - name: Set up Go
-      uses: actions/setup-go@v2-beta
+      uses: actions/setup-go@v2
       with:
         go-version: '^1.7'
 
     - name: Check out code
-      uses: actions/checkout@9a3a9ade
+      uses: actions/checkout@v2
       with:
         submodules: true
 
     - name: Clean up extra files
       run: rm ./testcases/*.go
+      
+    - name: Download deps
+      run: go mod download
 
     - name: Run golangci-lint
       uses: actions-contrib/golangci-lint@v1
@@ -31,9 +34,6 @@ jobs:
       with:
         golangci_lint_version: 'v1.23.6'
 
-    - name: Download deps
-      run: go mod download
-
     - name: Run tests
       run: go test -race -v ./...