add .github/workflows/go-check.yml

.github/workflows/go-check.yml

+# File managed by web3-bot. DO NOT EDIT.
+# See https://github.com/protocol/.github/ for details.
+
+on: [push, pull_request]
+
+jobs:
+  unit:
+    runs-on: ubuntu-latest
+    name: Go checks
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-go@v2
+        with:
+          go-version: "1.16.x"
+      - name: Install staticcheck
+        run: go install honnef.co/go/tools/cmd/staticcheck@be534f007836a777104a15f2456cd1fffd3ddee8 # v2020.2.2
+      - name: Check that go.mod is tidy
+        run: |
+          cp go.mod go.mod.orig
+          cp go.sum go.sum.orig
+          go mod tidy
+          diff go.mod go.mod.orig
+          diff go.sum go.sum.orig
+      - name: go vet
+        if: ${{ success() || failure() }} # run this step even if the previous one failed
+        run: go vet ./...
+      - name: staticcheck
+        if: ${{ success() || failure() }} # run this step even if the previous one failed
+        run: |
+          set -o pipefail
+          staticcheck ./... | sed -e 's@\(.*\)\.go@./\1.go@g'
+