meta: build different GOOSes in CI

First pass at #37 without support for cross-compilation of tests

Signed-off-by: evalexpr <wilkinsphysics@gmail.com>

.github/workflows/linux.yml

@@ -28,20 +28,18 @@ jobs:
     - name: Basic build
       run: go build ./cmd/...
 
+    - name: macOS build
+      env:
+        GOOS: darwin
+        GOARCH: amd64
+      run: go build ./cmd/...
+
+    - name: Windows build
+      env:
+        GOOS: windows
+        GOARCH: amd64
+      run: go build ./cmd/...
+
     - name: Test build
       run: go test ./...
 
-    - uses: k0kubun/action-slack@v2.0.0
-      with:
-        payload: |
-          {
-            "attachments": [{
-              "text": "${{ job.status }}: ${{ github.workflow }} <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ env.COMMIT_DATE }} #${{ env.COMMIT_NUMBER_OF_DAY }}> " +
-                      "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
-                      "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
-              "color": "danger"
-            }]
-          }
-      env:
-        SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-      if: failure() && github.event_name == 'push'