Drop Python 3.5 testing from CI

Author: pradyunsg

.github/workflows/check.yml

@@ -31,9 +31,6 @@ jobs:
     - uses: actions/setup-python@v2
       with:
         python-version: 2.7
-    - uses: actions/setup-python@v2
-      with:
-        python-version: 3.5
     - uses: actions/setup-python@v2
       with:
         python-version: 3.6