Upgrade GitHub actions

Closes #633

.github/workflows/release.yml

@@ -10,10 +10,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
 
       - name: Set up Go
-        uses: actions/setup-go@v1
+        uses: actions/setup-go@v2
         with:
           go-version: 1.17.x
 

.github/workflows/test.yml

@@ -10,13 +10,13 @@ jobs:
     runs-on: ${{matrix.platform}}
     steps:
       - name: Set up Go ${{matrix.go-version}}
-        uses: actions/setup-go@v1
+        uses: actions/setup-go@v2
         with:
           go-version: ${{matrix.go-version}}
         id: go
 
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
 
       - name: Download Go modules
         run: go mod download