Update ci.yml (#286)

Expand matrix to 3 os x 3 go versions.

closes #203

.github/workflows/ci.yml

@@ -1,4 +1,4 @@
-# GitHub Actions - CI for Go to build & test.  See ci-go-cover.yml and linters.yml for code coverage and linters.
+# GitHub Actions - CI for Go to build & test.  See ci-go-cover.yml and safer-golangci-lint.yml for more.
 # https://github.com/fxamacker/cbor/workflows/ci.yml
 name: ci
 on: [push]
@@ -10,17 +10,27 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [macos-latest, ubuntu-latest]
+        os: [macos-latest, ubuntu-latest, windows-latest]
+        go-version: [1.14.x, 1.15.x, 1.16.x]
+
     steps:
+    - name: Install Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: ${{ matrix.go-version }}
+
     - name: Checkout code
-      uses: actions/checkout@v1
+      uses: actions/checkout@v2
       with:
         fetch-depth: 1
+
     - name: Get dependencies
       run: go get -v -t -d ./...
+
     - name: Build project
       run: go build ./...
+
     - name: Run tests
       run: |
         go version
-        go test -short -race -v ./...
+        go test -race -v ./...