Merge pull request #309 from searxng/ci-python-3.10.0-rc.2

[ci] add Python 3.10.0-rc.2

.github/workflows/integration.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-20.04]
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version:  ["3.6", "3.7", "3.8", "3.9", "3.10.0-rc.2"]
     steps:
     - name: Checkout
       uses: actions/checkout@v2