Install from source in CI

Author: eriknw

.github/workflows/test.yml

@@ -17,8 +17,8 @@ jobs:
         # os: ["ubuntu-latest", "macos-latest", "windows-latest"]  # Waiting on builds
         os: ["ubuntu-latest"]
         python-version: ["3.8", "3.9", "3.10"]
-        source: ["conda-forge"]
-        graphblas-version: ["6.1.3"]
+        source: ["source"]  # ["conda-forge"]
+        graphblas-version: ["6.2.0.beta2"]
     steps:
     - name: Checkout
       uses: actions/checkout@v2