add coverage using goveralls

.github/workflows/go.yml

@@ -8,16 +8,21 @@ on:
 
 jobs:
 
-  build:
-    name: Build
+  build_and_test:
+    name: Build and test
     runs-on: ubuntu-latest
-    steps:
 
-    - name: Set up Go 1.13
+    strategy:
+      fail-fast: false
+      matrix:
+        go: ['1.11', '1.12', '1.13', '1.14']
+
+    steps:
+    - id: go
+      name: Set up Go
       uses: actions/setup-go@v1
       with:
-        go-version: 1.13
-      id: go
+        go-version: 1.13  # ${{ matrix.go }}
 
     - name: Check out code into the Go module directory
       uses: actions/checkout@v2
@@ -26,4 +31,19 @@ jobs:
       run: go build -v .
     
     - name: Test
-      run: go test -v .
+      run: go test -v -coverprofile=profile.cov .
+
+    - name: Send coverage
+      uses: shogo82148/actions-goveralls@v1
+      with:
+        path-to-profile: profile.cov
+        parallel: true
+
+  # notifies coveralls that all test jobs are finished
+  finish:
+    needs: test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: shogo82148/actions-goveralls@v1
+        with:
+          parallel-finished: true