Update CI to test on version 1.11

Author: brenhinkeller

.github/workflows/ci.yml

@@ -18,9 +18,9 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.8'
           - '1.9'
           - '1.10'
+          - '1.11'
         os:
           - ubuntu-latest
           - macOS-latest