using codecov for tests

.github/workflows/codecov_test.yml

@@ -0,0 +1,18 @@
+name: Test and coverage
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 2
+      - uses: actions/setup-go@v3
+        with:
+          go-version: '1.17'
+      - name: Run coverage
+        run: go test -race -coverprofile=coverage.out -covermode=atomic ./...
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v2

.gitignore

@@ -1,4 +1,5 @@
 /coverage/
 /c.out
-hermes
+/coverage.out
+/hermes
 dist/