sync: update CI config files (#30)

.github/workflows/go-check.yml

@@ -16,11 +16,12 @@ jobs:
         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
+          if [[ -n $(git ls-files --other --exclude-standard --directory -- go.sum) ]]; then
+            echo "go.sum was added by go mod tidy"
+            exit 1
+          fi
+          git diff --exit-code -- go.sum go.mod
       - name: gofmt
         if: ${{ success() || failure() }} # run this step even if the previous one failed
         run: |

.github/workflows/go-test.yml

@@ -32,7 +32,7 @@ jobs:
         if: ${{ matrix.os == 'ubuntu' }} # speed things up. Windows and OSX VMs are slow
         run: go test -v -race ./...
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@fcebab03f26c7530a22baa63f06b3e0515f0c7cd # v1.3.1
+        uses: codecov/codecov-action@967e2b38a85a62bd61be5529ada27ebc109948c2 # v1.4.1
         with:
           file: coverage.txt
           env_vars: OS=${{ matrix.os }}, GO=${{ matrix.go }}