Merge remote-tracking branch 'upstream/master'

Author: Alexander Ignatov

.github/workflows/unittests.yml

@@ -5,7 +5,9 @@ name: Unit Tests
 
 on:
   push:
-    branches: [ master ]
+    branches:
+      - master
+      - ci
   pull_request:
     branches: [ master ]
 
@@ -15,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.8.15, 3.9.16, 3.10.9, 3.11]
 
     steps:
     - uses: actions/checkout@v2