Add coverage job

.github/workflows/go.yml

@@ -1,7 +1,7 @@
 name: Go
 on: [push, pull_request]
 jobs:
-  build:
+  test:
     name: Test
     strategy:
       matrix:
@@ -13,17 +13,12 @@ jobs:
       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@v2
 
     - name: Test
-      run: go test -v -coverprofile=coverage.out ./ -count=1
-
-    - name: Report coverage
-      run: |
-        bash <(curl -s https://codecov.io/bash)
+      run: go test -v ./ -count=1
 
    # - name: Test with GC
    #   run: go test -v ./ -count=1
@@ -32,3 +27,18 @@ jobs:
 
    # - name: Test with race detector
    #   run: go test -v -race ./ -count=1
+  coverage:
+    name: Coverage
+    runs-on: ubuntu-latest
+    steps:
+      - name: setup Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: 1.15
+      - name: checkout
+        uses: actions/checkout@v2
+      - name: measure coverage
+        run: go test -v -coverprofile=coverage.out ./ -count=1
+      - name: report coverage
+        run: |
+          bash <(curl -s https://codecov.io/bash)