Expand matrix.

Author: faustomorales

.github/workflows/ci.yaml

@@ -7,8 +7,8 @@ jobs:
     name: Build Package
     strategy:
       matrix:
-        python: ['3.7']
-        os: [windows-latest]
+        python: ['3.7', '3.8', '3.9', '3.10']
+        os: [windows-latest, macos-latest, ubuntu-20.04]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout Code