ci: add 3.5.0 to test suite (#136)

Author: spacewander

.github/workflows/ci.yml

@@ -23,6 +23,8 @@ jobs:
             conf: Procfile-single-enable-v2
           - version: 3.4.0
             conf: Procfile-single-enable-v2
+          - version: 3.5.0
+            conf: Procfile-single-enable-v2
           - version: 3.4.0
             conf: Procfile-single-enable-tls
           - version: 3.4.0