Try out RF 4.1.1rc1

Author: aaltat

.github/workflows/CI.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         python-version: [3.6, 3.9, pypy3, 3.10.0-rc.1]
-        rf-version: [4.0.2, 4.1.0]
+        rf-version: [4.0.2, 4.1.1rc1]
 
     steps:
     - uses: actions/checkout@v2